Ch07 Anatomy and Physiology.docx

Chapter Anatomy and Physiology Unit Summary After students complete this chapter and the related course work they will be able to describe and apply in context the body planes topographical anatomy directional terms and anatomic position Students will be able to identify basic anatomic structures and related functions and describe each body system discussing the roles of the structures within these systems and the interaction of body systems in maintaining the life-support chain Students will be able to discuss possible consequences of illness and injury of these structures and systems on proper functioning of the body National EMS Education Standard Competencies Anatomy and Physiology Integrates a complex depth and comprehensive breadth of knowledge of the anatomy and physiology of all human systems Knowledge Objectives Understand the body s topographic anatomy including the anatomic position and the planes of the body p List the planes and sections of the body including frontal sagittal midsagittal transverse cross section and longitudinal p List and define terms related to specific areas of the body pp - Explain the following directional terms right left superior inferior lateral medial proximal distal superficial deep anterior ventral posterior dorsal palmar plantar and apex pp - Describe movement and positional terms including abduction adduction hyperflexion and hyperextension pp - Describe the prone supine Trendelenburg shock Fowler and recovery positions of the body pp - Describe the topography of the abdominal region including the four abdominal quadrants and the nine abdominal regions pp - Discuss the atomic composition of the body including bonding and chemical reactions pp - Discuss the chemical composition of the body including key substances enzymes carbohydrates lipids proteins nucleic acids and trace elements pp - Discuss cell structure and function as it relates to the practice of paramedicine pp - Describe the anatomy and physiology of the cell as well as the cellular environment pp - Discuss cell transport mechanisms including diffusion osmosis facilitated diffusion active transport endocytosis and exocytosis pp - Discuss the life cycle of a cell including interphase mitosis cytokinesis and differentiation pp - List and describe the types of tissues found in the body epithelial tissue connective tissue muscle tissue neural tissue and membranes pp - Discuss the anatomy and the physiology of the skeletal system including types of bones embryonic skeleton maturation bone growth and maintenance and related hormones major subdivisions of the skeleton components of the skeleton and classification and types of joints pp - Discuss the anatomy and physiology of the muscular system including gross and microscopic anatomy actions of muscles contraction of skeletal muscle fiber and major muscles of the body pp - Discuss the anatomy and physiology of the respiratory system including the structure and function of the nasal cavities pharynx larynx speaking mechanism trachea bronchial tree lungs alveoli and pulmonary capillaries pp - Describe the process of gas exchange in the alveoli p Discuss the concept of respiration pp - Discuss acid base balance and how it relates to respiration pp - Describe the concept of hypoxic drive p Discuss the concept of ventilation including pulmonary volumes and diffusion of gases pp - Explain the brainstem s role in regulating respiration p Explain how the level of carbon dioxide in the blood and the blood s pH relate to ventilation pp - Discuss the anatomy and physiology of the circulatory system including the composition and function of blood the heart and the blood vessels as well as the blood groups pp - Discuss the concepts of afterload stroke volume and cardiac output p Discuss the Frank-Starling mechanism p Discuss the anatomy and physiology of the lymphatic and immune system including the formation of lymph the locations and function of lymph nodes and the spleen innate versus adaptive immunity humoral versus cell-mediated immunity acquired versus genetic immunity and other mechanisms of protection including B cells T cells vaccinations and flora pp - Discuss the anatomy and physiology of the nervous system including the central and peripheral nervous systems as well as sensory function pp - Describe the anatomy and physiology of the integumentary system including function layers of the skin and other structures present in the skin pp - Explain the anatomy and physiology of the digestive system including general function organs and structures involved in digestion and the process of digestion pp - Discuss the anatomy and physiology of the endocrine system including endocrine and exocrine glands chemistry of hormones regulation of hormone secretion and the roles of hormones in various processes in the body pp - Describe the anatomy and physiology of the urinary system including its components general function the process of urine formation and the role of the kidneys in maintaining blood volume blood pressure pH and electrolyte balance pp - Explain the concept of fluid balance as well as the purpose and mechanisms for maintaining homeostasis p Discuss the anatomy and physiology of the genital system including the hormones and structures involved in reproduction the menstrual cycle spermatogenesis and oogenesis gestational changes and fetal circulation and respiration pp - Discuss the relationship between nutrition metabolism and body temperature including methods of heat generation and loss fever the role of the hypothalamus and cellular metabolism pp - Skills Objectives There are no skills objectives in this chapter Readings and Preparation Review all instructional materials including Chapter of Nancy Caroline s Emergency Care in the Streets Seventh Edition and all related presentation support materials Consider a quick read of http www brainrules net from John Medina s New York Times best seller Brain Rules Click on Brain Rules and then scroll down to the list of rules Rule is about the importance of visuals in learning Visuals will add greater understanding student-centered activity and fun to this chapter Support Materials Lecture PowerPoint presentation Case Study PowerPoint presentation Several copies of a human body diagram anterior posterior and lateral if possible for distribution in activities and assessments Have several copies for each student as they can serve as a template for many activities and assessments If available consider using pages from Human Anatomy Physiology Coloring Workbook Third Edition Available from http www jblearning com the ISBN for this product is - - - - Enhancements Direct students to visit the companion website to Nancy Caroline s Emergency Care in the Streets Seventh Edition at http www paramedic emszone com for online activities Direct students to the following websites Bassett Collection of Stereoscopic Images of Human Anatomy Stanford University http lane stanford edu biomed-resources bassett index html bassett FbassettView html Fbn D - Simple interactive tools for body systems http www getbodysmart com menu html Heart and lung animation http www smm org heart heart top html Human bone illustrations http homes bio psu edu people faculty strauss anatomy skel skeletal htm Fracture illustrations http gentili net fracturemain asp Content connections Inform students that a thorough understanding of anatomy and physiology will help them understand and apply concepts of pathophysiology in subsequent lessons It is also the foundation for determining possible consequences of the mechanism of injury and nature of illness as they assess patients in the field Nearly every chapter has extensive relevance to a thorough foundation in anatomy and physiology Cultural considerations While teaching anatomy and physiology keep in mind that students may assume that all people have the same physical internal structures Other chapters point out the cultural differences students need to consider to be most effective in assessment and care While we think of culture largely as a learned set of behaviors some cultures do have physical differences Some groups of people such as those born with physical differences eg dwarfism Down syndrome and hundreds of other conditions often form subcultures for social support and networking Consider challenging your student groups to learn more Ask students to select or assign them a condition for which subcultures exist and to research the physical differences in this group Here are some links to get started There are more than medical conditions that can cause the short stature known as dwarfism Little People of America LPA is a national nonprofit organization that provides support and information to people of short stature and their families http www lpaonline org Dwarfism and common medical conditions http web memberclicks com mc page do sitePageId orgId lpamrs Down syndrome and common medical conditions http www ndss org index php option com content view category id associated-conditions Use of correct terminology for people with Down syndrome http www ndss org index php option com content view article id Itemid dd Teaching Tips Images are integral to the retention of material Prepare ahead of time and consider incorporating one or more of the web links mentioned in the Enhancements section Choosing a variety of approaches including charts interactive exercises and group- and self-assessments will allow students to organize the new information and identify areas needing more review Including multiple activities with visual components will reduce learning time and increase retention See the Student presentation and Group activities sections for suggestions This chapter is particularly visuals friendly and with instructor guidance students can engage in creative fun learning Unit Activities Writing activities Using the systems researched in the Group activities section or selecting another system structure or organ have each student or group of students write one or two paragraphs on one illness and one injury that could directly affect this organ structure What would they expect to see Open up the presentations to class discussion if time allows Student presentations Ask students to present their writing assignment to the class requiring them to also prepare a one-page self-assessment to be distributed with the presentation Group activities Assign a body system to each group with instructions to create a presentation for the whole class on that system Each group should be given the same guidelines and questions that must be answered within the presentation Each group must make a visual representation of their system Suggestions include a life-size cardboard cutout of a student labeled with that system s components Another suggestion might include each group member making a cardboard or paper cutout of one of the organs or structures in the assigned system and taping it to his or her clothing in the appropriate place as the group presents their project to the class Questions to consider include Which structures are within this system How does each structure work independently How does each structure interact with the other parts of this system What other systems interact with this system Describe at least one function that involves another system Pre-Lecture You are the Medic You are the Medic is a progressive case study that encourages critical-thinking skills Instructor Directions Direct students to read the You Are the Medic scenario found throughout Chapter You may wish to assign students to a partner or a group Direct them to review the discussion questions at the end of the scenario and prepare a response to each question Facilitate a class dialogue centered on the discussion questions and the Patient Care Report You may also use this as an individual activity and ask students to turn in their comments on a separate piece of paper Lecture I Introduction A Knowledge of anatomy and physiology is necessary for every patient encounter B Anatomy is the study of the structure and makeup of the organism Gross anatomy studies organs and their locations in the body Microscopic anatomy studies the tissue and cellular components that cannot be seen with the naked eye C Physiology is the study of the processes and functions of the body Body systems operate simultaneously and rely on a myriad of interactions to work to maintain homeostasis a Homeostasis State of balance in which organs and systems can function effectively b Maintaining homeostasis preserves conditions necessary for normal life processes to function correctly such as temperature and acid base balance II Topographic Anatomy A Refers to superficial landmarks of the body B Terms apply to the body in anatomic position C Anatomic position Patient stands facing you arms at the side with the palms of the hands forward Used as common starting point Ensures that everyone refers to the body in same way D Left and right refer to the patient s left and right E Planes of the body Anatomic planes are imaginary straight lines that divide the body There are three main axes of the body depending on how it is divided a Coronal plane divides the body into a front portion and a back portion b Transverse axial plane divides the body into a top portion and a bottom portion c Sagittal lateral plane divides the body into a left portion and a right portion d The midsagittal plane midline is a special type of sagittal plane where the body is cut in half leaving equal left and right halves i Nose and naval are on this imaginary line e A cross section is the product of slicing an object across or perpendicular to its long axis i Similar to how you would cut a tree to view its rings f A longitudinal section is a view of an object cut along its long axis F Specific areas of the body Many body areas are given specific names Familiarizing yourself with these names will help you a Communicate with other professionals b Break down other names as many of these terms are used as root words The remainder of the body is classified into regions that clinically describe them Refer to Table for a list of terminology related to specific areas of the body G Directional terms Correct directional terms are needed to discuss a Where an injury is located b How pain radiates Directional terms are paired as opposites They indicate the distance and direction from the patient s midline Right and left a Refers to the patient s right and left sides not to yours Superior and inferior a Superior is nearer to the head and inferior is nearer to the feet Lateral and medial a Lateral is farther from the midline and medial is nearer to the midline Proximal and distal a Proximal is nearer to the trunk and distal is farther from the trunk Superficial and deep a Superficial is nearer to or on the skin and deep is farther inside the body and away from the skin Anterior and posterior a Anterior is the belly side of the body i Also called ventral b Posterior is the spinal side i Including back of the hand ii Posterior is also called dorsal Palmar and plantar a The front region of the hand is referred to as the palm or palmar surface The bottom of the foot is referred to as the plantar surface Apex a The tip of a structure H Movement and positional terms Range of motion a Full distance a joint can be moved Flexion a Brings the distal point of an extremity toward the trunk Extension a Returns a body part from flexion to the anatomic position Abduction a Moves an extremity away from midline Adduction a Moves an extremity toward midline Hyperflexion a Flexed to or beyond normal range of motion Hyperextension a Extended to or beyond normal range of motion Supination a Turning the palms upward Pronation a Turning the palms downward Internal rotation a Turning an extremity medially toward the midline External rotation a Turning an extremity away from the midline I Other directional terms Bilateral a A body part that appears on both sides of the midline b Examples eyes ears hands feet lungs kidneys Unilateral a Body part that appears on only one side of body b Examples spleen is on the left side liver is on the right Abdomen is divided into a Right upper quadrant b Left upper quadrant c Right lower quadrant d Left lower quadrant J Anatomic positions Prone a Lying face down Supine a Lying face up Trendelenburg position a Named after a German surgeon Friedrich Trendelenburg at the turn of the th century i Placed his patients in supine position on an incline with feet higher than head b Keeps blood in the core of the body c The patient is on a backboard or stretcher with the feet to higher than the head Shock position a Modified Trendelenburg position b The head and torso are supine and the lower extremities are elevated to to help increase blood flow to the brain Fowler s position a Sitting up with knees bent b Helps patients breathe easier and to control the airway c Named after a US surgeon George R Fowler at the end of the th century Recovery position a Lying on the side with bottom arm extended straight and the head lying on it b The top knee is bent angling the patient s body slightly toward the floor c Used to help maintain a clear airway in an unresponsive patient d When a patient is breathing on his or her own this position helps prevent aspiration of vomitus III Atoms Molecules and Chemical Bonds A Chemistry focuses on the composition of matter and changes in its composition Chemicals of the body include water proteins carbohydrates lipids nucleic acids salts and foods drinks and medications Matter is anything that takes up space and has mass a Includes liquids gases and solids both inside and outside the body Elements are fundamental substances that compose matter a Refer to Table for a list of major and trace elements required by the human body Atoms are the smallest units of an element and vary in size and weight a Interact and combine with other atoms by forming chemical bonds B Atomic structure Atoms consist of protons neutrons and electrons a Protons and neutrons are similar in size and mass b Protons have a positive electrical charge c Neutrons are electrically neutral uncharged d Electrons have a negative electrical charge e Atoms normally contain equal numbers of protons and electrons Atomic number is the number of protons in an atom Atomic weight of an element s atom is the number of protons and neutrons in its nucleus An isotope is an element s atoms that have nuclei with the same number of protons but different numbers of neutrons a Isotopes may or may not be radioactive b Nuclei of certain isotopes radioisotopes emit subatomic particles or radiation c Radiation is identified as one of three forms i Alpha ii Beta iii Gamma which is the most penetrating type similar to X-rays C Molecules Molecules are chemical structures that consist of atoms held together by covalent bonds When two atoms of the same element bond they produce molecules of that element a Examples include hydrogen oxygen or nitrogen molecules D Chemical bonds Atoms can bond with other atoms by using chemical bonds that result from interactions between their electrons Atoms may gain lose or share electrons a Atoms that either gain or lose electrons are called ions Ionic bonds a Form between ions b Ions with a positive charge are cations c Ions with a negative charge are anions d Oppositely charged ions attract each other to form an ionic bond Covalent bonds a Form when atoms complete their outer electron shells by sharing electrons b Atoms do not lose or gain electrons c A single covalent bond has a single pair of shared electrons d A double covalent bond has two pairs of shared electrons e Polar molecules have equal numbers of protons and electrons but one end of the molecule is slightly negative while the other end is slightly positive i Example of a polar molecule is water ii A hydrogen bond is the attraction of a positive end of a polar molecule with the negative end of another polar molecule iii Hydrogen bonds are weak at body temperature and important in protein and nucleic acid structure Compounds are molecules made up of different bonded atoms Numbers and types of atoms in a molecule are represented by a molecular formula Structural formulas are used to signify how atoms are joined and arranged inside molecules a Single bonds are represented by single lines b Double bonds are represented by double lines E Types of chemical reactions Synthesis reactions a When two or more reactants atoms bond to form a more complex product or structure b Synthesis requires energy c Synthesis is important for growth and the repair of tissues d Synthesis is symbolized as A B AB Decomposition reactions a Occur when bonds within a reactant molecule break forming simpler atoms molecules or ions b Decomposition reactions occur during digestion breaking down molecules of sugars proteins and fats into smaller fragments before absorption begins c Decomposition is symbolized as AB A B Exchange reactions a Reactions in which parts of the reacting molecules are shuffled around to produce new products b Exchange reactions are symbolized as AB CD AD CB Reversible reactions a Reactions in which the products of the reaction can change back into the reactants they originally were F Enzymes Enzymes make chemical reactions possible a Promote chemical reactions by lowering the activation energy requirements b Belong to a class of substances called catalysts G Acids bases and the pH scale Electrolytes are substances that release ions in water Acids are electrolytes that release hydrogen ions in water eg hydrochloric acid Bases are electrolytes that release ions that bond with hydrogen ions eg sodium hydroxide In body fluids the concentrations of hydrogen and hydroxide ions greatly affect chemical reactions a These reactions control certain physiologic functions such as blood pressure and breathing rates pH values are a measure of hydrogen ion concentrations a pH scale ranges from to b The midpoint is considered to be neutral neither acidic nor alkaline c Measurements of less than pH are considered acidic d Measurements of more than pH are considered basic or alkaline pH of blood usually ranges from to Acidosis is caused by blood pH lower than a If pH falls below coma may occur Alkalosis is caused by blood pH higher than a If pH rises above it causes uncontrollable and sustained skeletal muscle contractions Chemicals that resist pH changes are called buffers IV Chemical Constituents of Cells A Chemicals can be divided into two groups Organic Chemicals that always contain the elements carbon and hydrogen a Generally also contain oxygen Inorganic Any chemicals that do not contain carbon and hydrogen Inorganic substances release ions in water a Also called electyrolytes Many organic substances also dissolve in water a Dissolve better in alcohol or ether b Nonelectrolytes Organic substances that dissolve in water usually do not release ions B Inorganic substances Inorganic substances in body cells include oxygen carbon dioxide compounds known as salts and water Water is the most abundant compound in the human body Solutes are substances that dissolve in water The watery aqueous portion of the blood carries vital substances such as oxygen salts sugars and vitamins among the digestive tract respiratory tract and the cells Oxygen enters the body through the respiratory organs and is transported to the cells by red blood cells in the blood Carbon dioxide is produced as a waste product and exhaled via the lungs Salts are compounds of oppositely charged ions that are abundant in tissues in fluids Ions required by the body and supplied in salts include a Sodium chloride calcium magnesium phosphate carbonate bicarbonate potassium and sulfate Refer to Table for a list of common inorganic molecules C Organic substances Many organic molecules are made up of long chains of carbon atoms linked by covalent bonds Carbon atoms generally form additional covalent bonds a Usually with hydrogen or oxygen atoms b Also nitrogen phosporus sulfur or other elements less common Carbohydrates a Provide much of the energy required by the body s cells b Consists of carbon hydrogen and oxygen molecules c Contains carbon atoms joined in chains that vary with the type of carbohydrate d Carbohydrates with shorter chains are called sugars e Monosaccharides or simple sugars include glucose fructose galactose ribose and deoxyribose i Disaccharides are double sugars ii Oligosaccharides are created by adding more sugar chains iii Polysaccharides are complex carbohydrates that contain many simple joined sugar units eg plant starch Lipids a Not soluble in water and include fats phospholipids and steroids b A single fat molecule known as triglyceride consists of one glycerol molecule bonded to three fatty acid molecules c A phospholipid consists of a glycerol portion with fatty acid chains i Includes a phosphate group that is soluble in water and a fatty acid portion that is not soluble d Phospholipids are an important part of cell structures e Steroid molecules are large lipid molecules that share a distinctive carbon framework i Include cholesterol estrogen progesterone testosterone cortisol and estradiol Proteins a Most abundant organic components of the human body b Are vital for many body functions including structures and their functions energy enzymatic function defense antibodies and hormonal requirements c On cell surfaces some proteins combine with carbohydrates to become glycoproteins d Twenty-two different amino acids make up the proteins that exist in humans and most other living organisms e Peptides are protein molecules consisting of amino acids held together by peptide bonds f Polypeptides are formed from many amino acids bound into a chain Nucleic acids a Large organic molecules macromolecules that carry genetic information or form structures within cells b Store and process information at the molecular level inside cells c Two classes of nucleic acids are deoxyribonucleic acid DNA and ribonucleic acid RNA i DNA in your cells determines your inherited characteristics affects all aspects of body structure and function and encodes the information needed to build proteins d Three forms of RNA cooperate to manufacture specific proteins by using the information provided by DNA i Messenger RNA mRNA ii Transfer RNA tRNA iii Ribosomal RNA rRNA V Cell Physiology A Cells are the foundation of the human body Cells with a common job grow close to each other and form tissues Groups of tissues performing interrelated jobs form organs B Structure of the cell Two general classes of cells sex cells and somatic cells a Sex cells are either the sperm of males or the oocytes of females b Somatic cells include all the other cells in the human body Parts of the cell are the cell membrane the nucleus and the cytoplasm a Cell membrane encloses the cell its nucleus various organelles and its cytoplasm b Nucleus contains the cell s genetic material and controls its activities c Cytoplasm fills out the cell and its shape Cell membrane a Also called plasma membrane b Controls the movement of substances in and out of the cell c Cell membranes can be differentially permeable or semipermeable allowing certain elements to pass through while not allowing others to pass through d Lipids and proteins are the primary substances making up cell membranes and form a double layer of phospholipid molecules i The phosphate portion forms the outer surface ii The fatty acid portion forms the inner surface e Proteins in a cell membrane are classified according to where they are positioned i Cell membrane proteins may form receptors for hormones or growth factors transport substances across the cell membrane and form selective channels that determine which types of ions can enter or leave the cell ii Proteins may extend outward marking the cell as a component of a particular tissue or organ Cytoplasm a The substance that contains all the cellular contents between the cell membrane and the nucleus b Cytoplasm consists of cytosol and organelles excluding the nucleus i Cytosol is the fluid portion of cytoplasm and the site of many chemical reactions ii Organelles perform specific tasks related to cell structure growth maintenance and metabolism c The following organelles have specific actions that help the cell to carry out its activities i Centrioles are cylindrical structures composed of short microtubules that form the spindle-shaped structure needed for movement of DNA strands during cell division ii Cilia and flagella are structures that extend from certain cell surfaces a Cilia are hair-like and move in a coordinated sweeping motion to move fluids over the surface of tissues b Flagella are longer than cilia and often exist as only a single flagellum eg tail of sperm cell iii Ribosomes are on the outer membrane of the endoplasmic reticulum where protein synthesis occurs and are involved in the formation of proteins iv Endoplasmic reticulum ER is a network of intracellular membranes connected to the nuclear envelope that surrounds the nucleus a Smooth endoplasmic reticulum SER does not have ribosomes on its outer surface and synthesizes phospholipids and cholesterol b Rough endoplasmic reticulum RER does have ribosomes on its outer surface and synthesizes proteins v Golgi apparatus which consists of a stack of several flattened sacs has three main functions a Modifies and packages secretions ie hormones or enzymes that are released via exocytosis b Packages special enzymes inside vesicles for use in the cytosol c Renews or modifies the cell membrane vi Lysosomes are tiny sacs that dispose of cell wastes using digestive enzymes to break down nutrients or foreign particles eg bacteria vii Microfilaments are composed of the proteins actin and myosin are typically found in muscle cells and provide cell movement and contraction viii Mitochondria are the powerhouses of cells and have double membranes that play the central role in the production of energy via ATP a Outer mitochondrial membrane is smooth and the inner membrane has a series of folds called cristae b Central fluid-filled cavity is called the matrix and is enclosed by the inner membrane and cristae c Number of mitochondria in a particular cell varies depending on the cell s energy demands i Peroxisomes are sacs with enzymes that speed up many biochemical reactions ii They are abundant in the liver and kidneys ix Thick filaments are massive bundles of subunits composed of the protein myosin a Appear in muscle cells only where they interact with actin filaments to produce powerful contractions x Vesicles or vacuoles are bubble-like structures within the cytoplasm that are formed when a part of a cell membrane folds inward Nucleus a Contains DNA or the genetic instructions needed to synthesize the proteins that determine cell structures and functions b Nucleus of a cell is usually round with a double nuclear envelope that allows certain molecules to exit the nucleus c Nucleoplasm is the fluid within the nucleus that suspends the following structures i The nucleolus is a mini nucleus made up mostly of RNA and protein ii Chromatin are loosely coiled DNA and protein fibers that condense forming chromosomes VI Cellular Transport Mechanisms A Cell membrane permeability Cell membrane cell wall is selectively permeable allows some substances through Allows normal differences in concentrations between intracellular and extracellular environments to be maintained a Helps maintain homeostasis including temperature fluid balance and pH balance Various enzymes sugar molecules and electrolytes pass freely in and out of the cell a Electrolytes Chemicals that are dissolved in the blood and are made up of salt or acid substances that become ionic conductors when dissolved in a solvent eg water B Diffusion Movement of solutes particles from an area of high concentration to an area of low concentration to produce an even distribution of particles in the space available Depends on a Permeability of membrane to that substance b Concentration gradient The difference in concentrations of a substance on either side of the membrane C Osmosis Movement of a solvent eg water from an area of low solute concentration to one of high concentration Membrane is permeable to the solvent but not the solute Osmotic pressure The tendency of water to move by osmosis across a membrane a Crenation Cell shrinks abnormally as a result of too much water moving out of a cell b Lysis Cell swells and bursts as a result of too much water entering it Hypertonic Concentration of solute is higher within the cell than outside Hypotonic Less solute is present within the cell than outside Degree of difference between the two concentrations determine how a Much osmotic pressure is present b Quickly the two concentrations will tend to equalize Isotonic Concentrations on either side of the membrane are equal D Facilitated diffusion Process in which a carrier molecule moves a substance in or out of cells from areas of high concentration to areas of lower concentration Energy is not required E Active transport Movement of substance against a concentration gradient eg the cell membrane Requires energy and a carrier mechanism Movement is opposite the normal movement of diffusion Glucose and amino acids are absorbed via active transport Active transport mechanism may exchange one substance for another Endocytosis and exocytosis use energy from the cell to move substances into or out of the cell without crossing the cell membrane Endocytosis a A secretion from the cell membrane moves particles too large to enter the cell by other processes within a vesicle of the cell b Three forms i Pinocytosis cell drinking Cells take in small liquid droplets from the surrounding cell environment with a small indentation of the cell membrane ii Phagocytosis cell eating Cells take in solids instead of liquids iii Receptor-mediated endocytosis The movement of specific kinds of particles into the cell with protein molecules extending through part of the cell membrane to the outer surface Exocytosis a Opposite process to endocytosis b A substance stored in a vesicle is secreted from the cell VII The Cell Life Cycle A The life cycle of a cell includes the following four steps interphase cell division mitosis cytoplasmic division cytokinesis and differentiation Regulated via stimulation from hormones or growth factors most human cells divide to times before they die B Interphase During this period of preparation the cell duplicates most of its contents before it can actively divide C Cell division and cytoplasmic division Two types of cell division Meiosis and mitosis cytokinesis a Meiosis is part of gametogenesis the formation of egg or sperm cells i Reduces by half the number of chromosomes b Cell numbers are increased by mitosis the division of the nucleus of a cell and cytokinesis the division of the cytoplasm of a cell c All cells except egg and sperm cells are divided by mitosis stages of mitosis are i Prophase Two new centriole pairs move to opposite ends of the cell ii Metaphase Chromosomes line up near the middle between the centrioles with spindle fibers attached to them iii Anaphase Centromere sections of each chromosome are pulled apart to become individual chromosomes and move toward opposite ends of the cell iv Telophase Chromosomes lengthen and unwind with a nuclear envelope forming around them and nucleoli appearing in each newly formed nucleus d Cytoplasmic division cytokinesis begins during anaphase and continues through telophase i Cell membrane constricts down the middle portion of the cell ii Two newly formed nuclei are separated and half of the organelles are distributed into each new cell D Differentiation Differentiation is the process of specialization of a cell that makes each cell unique New cells must be generated in order for growth and tissue repair to occur Stem cells can divide repeatedly without specializing a Stem cells in certain organs may have the ability to heal the body in the future E Cell division and cancer Cell division and growth normally occurs at approximately the same rate as cell death Cell division and growth higher than the cell death rate causes tissues to enlarge a A tumor or neoplasm is a mass of tissue produced by abnormal cell growth and division b A benign tumor remains within the epithelium or capsule made of connective tissue i Benign tumors are seldom life threatening and can usually be surgically removed if it affects tissue function c Malignant tumors spread into surrounding tissues in a process called invasion i Malignant cells from the tumor of origin may travel to other organs or tissues metastasis to establish secondary tumors ii Metastasis is not easily controlled iii Malignancy often occurs when a normal gene mutates these modified genes are called oncogenes iv Cancer cells grow and multiply by taking nutrients and space from normal cells F Facilitating cellular metabolism All the body s cells tissues and organs regardless of their function require oxygen nutrients and the removal of wastes to perform their job Cells use oxygen to take the available nutrients and turn them into chemical energy Adenosine triphosphate ATP is involved in energy metabolism and is used to store energy Aerobic meaning with air metabolism uses oxygen a Waste products of aerobic metabolism are carbon dioxide and water An anaerobic without air state allows cells to operate despite no available oxygen a When available oxygen is limited to portions of the body cells will switch to anaerobic metabolism b A by-product of anaerobic metabolism is lactic acid which causes muscle burning during anaerobic exercise i Lactic acid is converted back to a useful energy source once oxygen is available ii Anaerobic metabolism can be supported in most cells for only to minutes VIII Types of Tissue A The human body is primarily made up of four major types of tissue epithelial connective muscle and nervous tissues Epithelial tissues cover body surfaces cover and line internal organs and make up the glands Connective tissues are widely distributed throughout the body filling the internal spaces and function to bind support and protect body structures Muscle tissues are specialized for contraction and include the skeletal muscles of the body the heart and the muscular walls of hollow organs Nervous tissues carry information from one part of the body to another via electrical impulses B Epithelial tissues Epithelial tissues include epithelia and glands Epithelium covers the surface of the skin and organs forms the inner lining of the body s cavities and also lines hollow organs A basement membrane is connective tissue that anchors epithelial tissues throughout the body Epithelial cells divide quickly aiding in wound healing Tightly packed epithelial cells protect body structures such as the outer skin and the lining of body cavities such as the mouth Epithelia perform four essential functions a Physical protection Protect exposed and internal surfaces from abrasion dehydration and destruction b Permeability Some epithelia are relatively impermeable whereas others are crossed easily by compounds of various sizes c Sensation Epithelia have a large sensory nerve supply d Specialized secretions Epithelial cells that produce secretions are called gland cells Various forms of epithelial tissues include a Simple squamous epithelium A single layer of thin and flattened cells with broad thin nuclei lines the alveoli of the lungs forms capillary walls lines blood and lymph vessels and covers membranes that line body cavities b Simple cuboidal epithelium A single layer of cube-shaped cells with round nuclei covers the ovaries lines many kidney tubules and glandular ducts and functions in secretion and absorption c Simple columnar epithelium Cells that are longer than wide composed of a single cellular layer with elongated nuclei located near the basement membrane and may have cilia on their surfaces found in female reproductive organs and digestive tract organs involved in secretion and absorption d Pseudostratified columnar epithelium Appear layered due to the nuclei being located at different levels cells vary in shape and usually reach the basement membrane usually has cilia and lines respiratory system passages and involved in secretion e Stratified squamous epithelium Thick layer with cells that flatten as they are pushed outward forms the epidermis with cells hardening as they age keratinization and also lines the mouth esophagus vagina and anus where cells remain soft and moist f Stratified cuboidal epithelium Up to three layers of cubed cells lines the mammary gland ducts sweat glands salivary glands pancreas and developing ovaries and seminiferous tubules g Stratified columnar epithelium Several layers of either columnar or cubed shapes found in the male urethra ductus deferens and areas of the pharynx h Transitional epithelium Changes in appearance in response to tension lines the urinary bladder ureters and superior urethra and prevents urinary tract contents from diffusing back into the internal body environment i Glandular epithelium Specialized cells that produce and secrete substances into ducts or body fluids found in exocrine glands which open onto surfaces or into the digestive tract or in endocrine glands which secrete into tissue fluid or blood Refer to Table for a list of types of epithelial tissues C Connective tissues Connective tissues vary greatly in appearance and several functions which include a Binding body structures b Providing support and protection c Creating frameworks d Filling body spaces e Storing fat f Producing blood cells g Transporting fluids and dissolved materials h Repairing damaged tissues i Protecting the body from infection Connective tissues have three basic components a Specialized cells b Extracellular protein fibers c A fluid known as a ground substance Extracellular protein fibers together with the ground substance constitute the matrix which surrounds the cells and accounts for the majority of connective tissue Connective tissues include bone cartilage and fat A type of fixed connective tissue cell is the star-shaped fibroblast that produces fibers via protein secretion into the extracellular matrix Fibroblasts produce three connective tissue fibers a Collagenous fibers Important in ligaments and tendons b Elastic fibers Common in body parts that are often stretched eg vocal chords c Reticular fibers Form delicate supporting networks in the spleen and other tissues Other types of cells found in connective tissue include a Mast cells Usually near blood vessels they release both heparin to prevent blood clotting and histamine for the inflammatory and allergic response b Macrophages Responsible for phagocytosis c Adipocytes fat cells Store body fat d Melanocytes Specialized cells in the deeper epithelium of the skin responsible for the production of melanin Classifications of connective tissues a Three general categories of connective tissue are connective tissue proper supporting connective tissues and fluid connective tissues b Connective tissue proper is divided into dense and loose connective tissues i Dense connective tissue Contains many collagenous fibers appears white has a fine network of elastic fibers and is very strong eg tendons and ligaments ii Loose connective tissue Includes adipose fat tissue areolar tissue and reticular connective tissue c Supporting connective tissue protects soft tissues and some or all of the body s weight and includes cartilage and bone i Cartilage is a rigid connective tissue with a gelatinous matrix that contains an abundance of fibers and it supports frames and attaches to many underlying tissues and bones ii Types of cartilage include hyaline cartilage on the ends of bones in many joints important for growth most common elastic cartilage flexible framework for ears and larynx and fibrocartilage very tough absorbs shock in the spinal column knees and pelvic girdle iii Bone is the most rigid type of connective tissue and consists of a matrix of connective tissue blood vessels and minerals ie calcium and phosphorus iv Bone marrow is the soft tissue that fills the inside of bones and it is the site of production of red blood cells cells platelets and most white blood cells v Bone cells or osteocytes consist of a dense and mineralized matrix d Fluid connective tissues blood or lymph have cells suspended in a water matrix i Blood contains formed elements red blood cells white blood cells and platelets suspended in a liquid extracellular matrix known as blood plasma ii Lymph forms as interstitial fluid enters the lymphatic vessels which return the lymph to the cardiovascular system D Muscle tissues Contract by shortening their elongated muscle fibers which moves body parts Three types of muscle tissue are skeletal muscle tissue smooth muscle tissue and cardiac muscle tissue a Skeletal muscle tissue Multinucleated cells skeletal muscle attaches to bones contracts when stimulated by nerve cells allows voluntary movements of body parts b Smooth muscle tissue Not under voluntary control composes hollow internal organ walls intestines stomach urinary bladder blood vessels uterus c Cardiac muscle tissue Also called myocardium is the thick contractile middle layer of the heart wall involuntary and makes up most of the heart relies on pacemaker cells or nodes of tissue in the conduction system for regular contraction E Nervous tissues Specialized for the conduction of electrical impulses from one region of the body to another Nervous tissue contain two basic types of cells neurons and neuroglia or glial cells a Neurons are the basic structure of neural tissue that respond to environmental changes by transmitting impulses along axons cellular processes to other neurons to muscles or to glands b Neuroglial cells divide and support nervous tissue components four types of neuroglia are astrocytes oligodendroglia microglia and ependymal cells IX Types of Membranes A Membranes form a barrier or an interface Epithelial membranes are thin structures made up of epithelium and underlying connective tissue that cover body surfaces and line body cavities four types of membranes are a Serous membrane Lines body cavities that lack an opening to the outside of the body ie thorax and abdomen secretes serous fluid which lubricates membrane surfaces b Mucous membrane Lines body cavities that open to the outside nose mouth digestive respiratory urinary and reproductive tubes secretes mucus c Cutaneous membrane The skin which covers the body surface d Synovial membrane Forms an incomplete lining within the cavities of the synovial joints X Organ Systems A Organs in each organ system work together to maintain homeostasis Organ systems include the skeletal muscular respiratory circulatory lymphatic nervous integumentary digestive endocrine urinary and genital systems XI The Skeletal System Anatomy A The skeleton gives us our recognizable human form and protects vital internal organs B Bones are the major structure of the skeletal system C Other tissues work with bones to provide the support framework of the skeleton Tendons are specialized tough cords or bands of dense white connective tissue that connects muscles to bones Ligaments are tough white bands of tissue that connect bones to each other Cartilage covers the ends of the bones where they form joints and is known as articular cartilage a Provides cushioning and allows the bones to move smoothly against each other D Overview of bones Bones are classified according to their shape as long bones short bones flat bones and irregular bones a Long bones include the femur tibia fibula ulna radius and humerus b Short bones include the carpal wrist bones and the tarsal ankle bones c Flat bones include certain skull bones ribs the sternum and the scapulae d Irregular bones include many facial bones the vertebrae in the spine and the pelvis Long bones consist of a shaft diaphysis the ends epiphyses and the growth plate epiphyseal plate which is the major site of bone elongation a Periosteum is a double layer of connective tissue that lines the outer surface of the bone and the inner surfaces are lined with endosteum Diaphysis of many bones includes the medullary cavity an internal cavity that contains a substance known as bone marrow a Most bone marrow in the long bones contains adipose fat tissue and is called yellow marrow b Bones of the axial skeleton and girdles contain red marrow where most red blood cells are manufactured Two main types of bone are compact solid bone and cancellous spongy bone a Compact bone i Mostly solid with few spaces ii Contains a central space called marrow cavity or marrow canal b Cancellous bone i Consists of a lacy network of bony rods called trabeculae ii Trabeculae are oriented along the lines of stress to increase the weight-bearing capacity of the long bones E Joints Joints articulations are formed wherever two long bones come in contact Consist of a Ends of the bones that make up the joint b Surrounding connecting and supporting tissue Most joints are named by combining the names of the two bones that form it a For example the sternoclavicular joint is the articulation between the sternum and the clavicle Joints are classified as slightly moveable amphiarthrotic freely movable diarthrotic or immovable synarthrotic a Most allow motion b Some bones fuse with one another at joints to form a solid immobile bony structure eg skull c Some joints have slight limited motion in which the bone ends are held together by fibrous tissue symphysis Joints are grouped according to the type of tissue binding them at their junctions a Fibrous joints Between bones that closely contact each other and are joined by thin dense connective tissue eg flat bones of the skull b Cartilaginous joints Connected by hyaline cartilage or fibrocartilage these joints include those that separate the vertebrae intervertebral disks c Synovial joints Allow free movement diarthrotic and have an outer layer of ligaments the joint capsule and an inner lining of synovial membrane that secretes synovial fluid which lubricates the joint i Have shock-absorbing fibrocartilage pads menisci ii May also have fluid-filled sacs bursae between tendons and underlying bony prominences such as in the knee or elbow Synovial joints are classified as a Ball-and-socket joints Shoulders and hips b Condyloid ellipsoidal joints Between the metacarpals and phalanges c Gliding plane joints Wrists and ankles d Hinge joints Elbow and phalanges e Pivot joints Between the proximal ends of the radius and ulna f Saddle joints Between the carpal and metacarpal bones of the thumb Joint capsule is the fibrous sac that holds the bone ends of a joint together Synovial membrane is the inner lining of the joint capsule that makes the thick lubricant called synovial fluid F Growth and development of bones Bones begin to form in utero at weeks Bone-forming cells osteoblasts develop depositing bony matrix around them once the matrix has surrounded the osteoblasts they are called osteocytes Bones develop from hyaline cartilage that is shaped similarly to the bones they will become Bone growth continues through adolescence Osteogenesis is the formation of bone The process of replacing other tissues with bone is called ossification and the process of bone formation is called endochondrial ossification Intramembranous ossification is the process for the formation of flat bones a Flat bones develop from connective tissue membranes that are replaced by spongy bone and then compact bone ie fontanelles or soft spots on an infant s skull When bones are growing the diaphyses meet the epiphyses at the epiphyseal plate Osteoblast and osteoclast activity is balanced so that the bones grow with uniformity G Axial skeleton Skeletal system is divided into two sections a Axial skeleton b Appendicular skeleton Axial skeleton forms the foundation on which the arms and legs are hung Components a Skull b Face c Thoracic cage d Vertebral column Appendicular skeleton Arms and legs their connection points pelvis Thorax a Encloses heart lungs and great vessels b Also called thoracic cavity c Part of the torso Most of the liver and spleen are protected by the lower ribs The spinal cord is contained in and protected by a bony spinal canal formed by the vertebrae The bones of the skeleton provide a framework for attachment of muscles The skeleton is also designed to allow motion of the body a Bones contact with each other at joints and with the help of muscles the body is able to bend and move The skull a At the top of the axial skeleton b The skull contains bones in anatomic groups i Auditory ossicles a Six bones function in hearing b Three are located on each side of the dead deep in cavities of temporal bone ii Cranium a Cranial vault consists of eight bones that encase and protect the brain the parietal temporal frontal occipital sphenoid and ethmoid bones b Foramen magnum Large opening at the base of the skull through which the brain and spinal cord connect iii Face c The bones of the skull are connected at special joints called sutures i The paired parietal bones join together at the sagittal suture ii The parietal bones abut the frontal bone at the coronal suture iii The occipital bone attaches to the parietal bones at the lambdoid suture iv Fontanelles Fibrous tissues that soften and expand during childbirth link the sutures a Tissues felt through the fontanelles are layers of the scalp and thick membranes overlying the brain b By the time a child reaches age years the sutures should have solidified and the fontanelles closed d Mastoid process Cone-shaped section of bone at the base of the temporal bone i Important site for attachment of various muscles Floor of the cranial vault a Three compartments Anterior fossa middle fossa posterior fossa b Crista galli Prominent bony ridge in the center of the anterior fossa and the point of attachment of the meninges that surround the brain c Cribriform plate of the ethmoid bone On either side of the crista galli the horizontal bone is perforated with numerous openings foramina for the passage of the olfactory nerve filaments from nasal cavity Facial bones a Frontal and ethmoid bones are part of the cranial vault and the face b Fourteen facial bones form the structure of the face i Do not contribute to cranial vault c Includes the following bones i Maxillae ii Mandible iii Zygoma iv Palatine v Nasal vi Lacrimal vii Vomer viii Inferior nasal concha d Facial bones i Protect eyes nose and tongue ii Provide attachment points for muscles that allow chewing e Zygomatic arch i Formed by the zygomatic process of the temporal bone and the temporal process of the zygomatic bone ii Lends shape to the cheeks Bones of the orbit a Cone-shaped fossae b Enclose and protect the eyes c Contains eyeball and the muscles that move it blood vessels nerves and fat d The frontal sphenoid zygomatic maxilla lacrimal ethmoid and palatine bones each form portions of the orbits e Blowout fracture i A blow to the eye that results in fracture of the floor of the orbit ii Floor of the orbit is extremely thin and breaks easily iii Force is transmitted away from eyeball to bone iv Blood and fat leak into maxillary sinus below Bones of the nose a Nasal cavity comprises portions of several of the facial bones including the frontal nasal sphenoid ethmoid inferior nasal concha maxilla palatine and vomer bones b The nasal septum separates the nostrils c Cavities associated with several bones the nose are called paranasal sinuses d The paranasal sinus contents drain into the nasal cavity e Sinusitis is inflammation of the paranasal sinuses Bones of the ear a Contained within the middle ear are the ossicles three tiny auditory bones b These bones are known as the hammer malleus anvil incus and stirrup stapes for their shapes Mandible and temporomandibular joint a Mandible i Movable bone comprising the lower jaw and containing the lower teeth ii Numerous muscles of chewing attach to the mandible b Temporomandibular joint TMJ i Condyloid joint where posterior condyle of the mandible articulates with the temporal bone ii Formed when a rounded bone fits into a similarly curved fossa iii Allows many different movements of the mandible Hyoid bone a Floats in the superior aspect of the neck just below the mandible i Not actually part of the skull b Supports the tongue c Serves as point of attachment for many important neck and tongue muscles d When damaged by blow to anterior neck a hoarse and low-volume voice may indicate airway swelling H Neck Supported by the cervical spine a First seven vertebrae of spinal column Esophagus and trachea windpipe lie in midline of the neck On either side of the trachea lie a Carotid arteries b Jugular veins c Nerves Useful landmarks of the neck a Adam s apple i Firm prominence in the center of the anterior surface of the neck ii Upper part of the thyroid cartilage iii More prominent in men b Cricoid cartilage i Firm ridge of cartilage inferior to the thyroid cartilage ii Somewhat difficult to palpate c Cricothyroid membrane i Soft depression between thyroid cartilage and cricoid cartilage in the midline of the neck ii Thin sheet of connective tissue fascia joining the two cartilages I The spinal column The spinal column or vertebral column is the central supporting structure of the body Composed of bones a Each called a vertebra i Vertebrae are named according to section of spine in which they lie ii Vertebrae are numbered from top to bottom From top down the spine is divided into five sections a Cervical spine i Formed by the first seven vertebrae C to C in the neck ii Skull rests on articulates with first cervical vertebrae atlas b Thoracic spine i Comprised of next vertebrae ii One pair of ribs is attached to each of the thoracic vertebrae c Lumbar spine Next five vertebrae d Sacrum i One bone formed by the fusion of five sacral vertebrae ii Joined to iliac bones of the pelvis with strong ligaments at sacroiliac joints to form the pelvis e Coccyx i Last four vertebrae ii Fused together iii Also called the tailbone The first cervical vertebra C a Called the atlas b Located directly beneath the skull c Provides support for the head d Atlanto-occipital joint i Where C articulates with the occipital condyles at the base of the skull ii Flexion extension and lateral bending are only motions of this joint The second cervical vertebra C a Known as the axis b Located at the point at which the head rotates left and right c An offshoot of C is the dens or odontoid process which fits into the enlarged vertebral foramen of the atlas i Atlas rotates around the axis at the dens Vertebrae numbered C through C form the cervical curve C is called the vertebra prominens a Has a large spinous process that may be seen and felt at the base of the neck Anterior part of each vertebra consists of a round solid block of bone called the body Posterior part of each vertebra forms a bony arch Vertebrae are connected by ligaments and between each vertebra is a cushion called the intervertebral disk a Ligaments and disks allow some motion b Also limit motion in protection of the spinal cord J The thorax Chest Formed by a Twelve thoracic vertebrae T to T b One pair of ribs is attached to each thoracic vertebra c Twelve pairs of ribs form the ribcage i Protects organs within the thorax and prevents collapse of the chest during breathing Upper seven pairs of ribs true ribs articulate with the thoracic vertebrae and attach to the sternum Eighth ninth and tenth ribs attach to the inferior portion of the preceding rib s cartilage instead of the sternum itself false ribs Remaining two pairs of ribs floating ribs are held in place by cartilage Anteriorly in the midline of the chest is the sternum a The superior border forms the easily palpable jugular notch i Location where the trachea enters the chest b The sternum has three components i Manubrium Upper section ii Elongated body iii Xiphoid process Narrow cartilaginous tip most inferior portion The largest structures in the thoracic cage are the heart lungs and great vessels a The heart lies directly behind the sternum retrosternal i Extends from the second to sixth ribs anteriorly ii Extends from the fifth to eighth thoracic vertebrae posteriorly iii Inferior border extends into left side of chest iv Diseased hearts may be larger or smaller b Superior and inferior venae cavae carry blood to the heart c Arch of the aorta and pulmonary artery exit the heart just beneath the manubrium of the sternum i Arch of the aorta lies along the left side of the spinal column as it descends in the abdomen d Esophagus lies behind the great vessels i Directly on the anterior aspect of the spinal column as it passes through the chest into the abdominal cavity K Appendicular skeleton Shoulder girdle a Attaches upper extremity to body b Made up of the scapula shoulder blade and clavicle collarbone c Acromion process protects the shoulder joint and provides a site of attachment for the clavicle and various shoulder muscles Shoulder joint a Ball-and-socket joint in which the head of the humerus articulates with the glenoid fossa which is part of the scapula b Four ligaments attach humeral head to glenoid fossa part of the scapula c Bursa Fluid-filled sac between tendon and bone that cushions and protects joints Upper extremity a Consists of i Arm commonly thought of as upper arm ii Forearm iii Wrist iv Hand v Fingers b Humerus i Bone of the upper arm ii Articulates proximally with glenoid fossa distally with radius and ulna at elbow joint iii Hinge joint can move in one plane only iv Several ligaments connect humerus radius and ulna at elbow joint v Fluid-filled bursa cushions and protects joint posteriorly Forearm and wrist a Forearm extends from elbow to wrist b Contains two bones i Radius a Located on lateral thumb side of forearm when forearm is in anatomic position b Radial head Proximal portion of radius c Distal portion contains a small bony protrusion stolid process to which ligaments of the wrist are attached ii Ulna Located on the little finger side of forearm c Wrist i Contains eight bones carpals triquetrum pisiform capitate lunate hamate trapezoid trapezium and scaphoid carpal navicular bones ii Carpal tunnel a Formed by the space bounded by the trapezium and hamate dorsally and the flexor retinaculum a sheath of tough connective tissue that forms the roof of the carpal tunnel on the palmar side b Tendons nerves and blood vessels lie within the carpal tunnel c Structures within the carpal tunnel include long flexor tendon to the fingers and the median nerve which supplies sensory and motor function to the radial half of the palm of the hand Hand a Metacarpals Bones that form the hand b Phalanges i Series of small bones in each finger ii Form hinge joints in fingers iii Three on each finger except thumb which has two c The carpometacarpal joint of the thumb is a saddle joint i Consists of two saddle-shaped articulating surfaces that are oriented at right angles to one another so that the complementary surfaces articulate with each other ii Movement in these joints can occur in two planes iii Arthritis commonly affects this joint resulting in stiffness and deformity L The pelvic girdle Also called pelvis Where lower limbs attach to axial skeleton Contains a ring of bones formed by sacrum and coxal pelvic bones a Sacrum is the posterior bone b Coxal bones are on either side Each coxa consists of three fused bones a Ilium is the largest portion of the hip bone i Called the iliac crest ii Joins the sacrum at the sacroiliac joint b Ischium is the lowest portion of the hip bone i L-shaped ii Supports the weight of the body when sitting c Pubis is the anterior portion of the hip bone i Forms an angle known as the pubic arch ii Two pubic bones join at the symphysis pubis Pelvis contains three joints a Two posterior sacroiliac joints i Where ilium connects with sacrum b Interior midline pubic symphysis i Lower midportion of the pelvic ring where the left and right sides fuse together Iliac crest Superior portion of the ilium Obturator foramen Opening between the ischium and pubis that contains several important nerves and muscles Pelvis supports the body s weight and protects internal organs a In a pregnant women it protects the fetus and provides a passageway for delivery M The lower extremity Thigh knee leg ankle foot toes Acetabulum is the socket that connects the pelvis to the lower extremity The thigh a Extends from the hip to the knee and contains the femur b The uppermost portion of the femur the femoral head articulates with the pelvis c The proximal femur consists of the neck greater trochanter and lesser trochanter The leg a Made of the tibia and fibula b Extends from the knee to the ankle c Tibia is the longer and thicker than the fibula and on the anterior surface of the leg shin d Medial malleolus forms the medial side of the ankle joint and lies at the distal end of the tibia e Fibula is posterior to the tibia and does not articulate directly with the femur but with the tibia at the head f Distal end of the fibula forms the lateral wall of the ankle joint the lateral malleolus The knee a Hinge joint b Menisci cover the margins of the tibia to cushion the articular surface c Anterior cruciate ligament ACL extends between the tibia and femur prevents abnormal anterior movement hyperextension of the tibia d Posterior cruciate ligament PCL prevents abnormal posterior displacement of the tibia e Surrounded by several fluid-filled bursae The ankle a The talus articulates with the tibia and fibula to form the ankle b Ankle tarsus is made up of seven bones called tarsals i Arranged so the talus bone moves freely where it joins the leg bones c Calcaneus i Heel bone ii Inferior and lateral to talus iii Provides additional support d A fibrous capsule surrounds the ankle joint i Medial and lateral portions are thickened to form ligaments e Movements include dorsiflexion and plantar flexion as well as limited inversion and eversion f Metatarsals and phalanges of the foot are arranged like bones of the hand i Toes have three phalanges each except big toe which has two g Ball of the foot is the junction between metatarsals and phalanges XII The Skeletal System Physiology A Bones serve several functions They Protect internal organs With muscles enable movement Store minerals a Particularly calcium Play role in forming blood cells and platelets B Bones consist of Collagen a Collagen fibers provide flexible strength like reinforcing rods in a concrete structure The mineral hydroxyapatite a A compound that contains calcium and phosphate b Mineral components provide strength to bear weight like concrete in a structure C In the marrow of certain types of bones special cells exist that can transform themselves into red blood cells white blood cells and platelets D Bones are a living substance with cells requiring a blood supply E During a person s life bones are constantly remodeled to meet the stresses placed on them Level of activity determines how they are remodeled XIII The Musculoskeletal System Anatomy A Provides the body s form upright posture movement Musculoskeletal refers to the bones and voluntary muscles of the body B Also protects vital internal organs C Muscles are a form of tissue that allow movement Over muscles in the musculoskeletal system D The type of muscle found here is called skeletal muscle Other types of muscle outside this system include smooth involuntary muscle and cardiac muscle E Skeletal muscle Forms the major muscle mass of the body Also called voluntary muscle a Under direct voluntary control of the brain b Can be stimulated to relax or contract at will Movement of the body results from skeletal muscle contraction or relaxation a Usually the result of several muscles acting simultaneously b Layers of fibrous connective tissue fascia separate individual skeletal muscles from other skeletal muscles and hold them in position Coverings of connective tissue a Fascia surrounds every muscle and may form cord-like tendons b Tendon fibers attach muscle to bones c Aponeuroses are broad sheets of fibers that may attach to bones or muscles d Many layers of connective tissue that enclose and separate skeletal muscles allow movement i Epimysium ii Perimysium iii Fascicles iv Endomysium Structure of skeletal muscle fibers a Thin elongated cylinders with rounded ends b Cell membrane sarcolemma lies above the cytoplasm sarcoplasm c Sarcoplasm is made up of many threadlike myofibrils arranged parallel to each other striations i Patterns of striation units along each muscle fiber are referred to as sarcomeres d Light bands I bands made up of thin filaments of actin e Dark bands A bands made up of thick filaments of myosin that overlap the actin f Central region H zone of thick filaments with a thickened area the M line that consists of proteins g Transverse tubules T-tubules are membranous channels extending inward and passing through the fiber h The sarcoplasmic reticulum and T-tubules activate muscle contraction when stimulated Neurologic structures a Motor neurons control effectors which include skeletal muscle b Neurons communicate with other cells by releasing neurotransmitters c Neuromuscular junction is the connection between a motor neuron and a muscle fiber d Motor end plate is formed by specialized muscle fiber membranes and has abundant mitochondria and nuclei e On receiving impulses the vesicles release neurotransmitters that stimulate muscle contraction Motor units a Made up of a motor neuron and the muscle fibers that it controls F Contraction of skeletal muscle Skeletal muscles contract when organelles and molecules bind myosin to actin causing a pulling action a Myofibrils move as actin and myosin slide which shortens muscle fiber and pulls on its attachments Required chemicals a Troponin and tropomyosin b Contractions cannot occur unless the position of the troponin tropomyosin complex changes to expose the active sites on F actin c Sliding filament model is so named because of the way sarcomeres shorten d Myosin filaments contain the enzyme ATPase which catalyzes the breakdown of ATP to ADP and phosphate releasing energy Contraction stimulus a Impulse that causes contraction of skeletal muscle is transmitted through motor neurons as a nerve impulse or action potential b Depolarization is the process of cells activating in response to the action potential c An electrochemical gradient across the cell membrane is known as being polarized d During repolarization the cell recreates the electrochemical gradient e Acetylcholine is the neurotransmitter that stimulates skeletal muscle to contract i Binds to certain protein receptors in the muscle fiber membrane increasing permeability to sodium ii These charged particles stimulate a muscle impulse f Muscle relaxation is caused by the decomposition of acetylcholine via the enzyme acetylcholinesterase Energy sources a ATP is regenerated from ADP and phosphate b Creatine phosphate accomplishes this with high-energy phosphate bonds c Creatine phosphate stores are exhausted rapidly when muscles are active d The muscles use the cellular respiration of glucose as energy to synthesize ATP Oxygen use and debt a Oxygen is required for the breakdown of glucose in the mitochondria b Red blood cells carry oxygen bound to hemoglobin molecules c The pigment myoglobin is synthesized in the muscles and combines with oxygen and temporarily stores it d With strenuous exercise oxygen is used to synthesize ATP e As lactic acid increases an oxygen debt develops f Oxygen debt is equivalent to the amount of oxygen that liver cells require to convert the lactic acid into glucose g Increased exercise raises the muscles capacity for glycolysis h Aerobic exercise increases the muscles capacity for aerobic respiration Muscle fatigue a Prolonged exercise may cause a muscle to become unable to contract b Lactic acid accumulation is the usual cause of muscular fatigue Production of heat a Most of the energy released in cellular respiration becomes heat Muscle responses a Muscle fiber will remain unresponsive until a certain strength of stimulation the threshold stimulus is applied b Contractile response of a fiber to an impulse is called a twitch i Consists of a period of contraction followed by a period of relaxation ii Two types of twitches The fatigue-resistant slow twitch and the fatigable fast twitch c Sustained contractions that have no relaxation are referred to as tetanic contractions or tetany Actions of skeletal muscles a Skeletal muscles cause unique movements based on the type of joint they attach to and where the attachment points are b At rest muscle fibers still undergo some sustained contraction muscle tone or tonus Origins and insertions a One end of a skeletal muscle fastened to a relatively immovable part origin at a moveable joint b The other end connects to a movable part insertion on the other side of the joint c During a contraction the insertion is pulled toward the origin d Flexion describes a decrease in the angle of a joint e Extension describes an increase in the angle of a joint Skeletal muscle interactions a Muscle that contracts to provide most of the movement is called the agonist b Other muscles synergists work with a prime mover to make its action more effective c Other muscles act as antagonists to prime movers causing movement in the opposite direction d Refer to Table for a list of the major muscles their locations and their functions XIV The Musculoskeletal System Physiology A Functions of the musculoskeletal system Contraction and relaxation of this system makes movement and manipulation of one s environment possible a Heat is a by-product of movement i Involuntary shaking of muscles shivering produces heat ii Shivering is an essential function Muscles protect the structures under them a Example The intestines are protected by the rectus abdominus muscles XV The Respiratory System Anatomy A Consists of all the structures of the body that contribute to respiration the process of breathing including the Nose Mouth Throat Larynx Trachea Bronchi Bronchioles Lungs where oxygen is passed to blood and carbon dioxide removed Diaphragm Muscles of chest wall Accessory muscles of breathing which permit normal respiratory movement B Upper airway The structures of the upper airway are located anteriorly and at the midline including the a Nose b Mouth c Tongue d Jaw e Oral cavity f Larynx g Pharynx Inspired air flows into the body through the mouth or nose The nasal cavity nasopharynx and oral cavity oropharynx connect posteriorly to form the pharynx throat The larynx voice box a Rigid hollow structure made of cartilage b Plays an important role in swallowing The pharynx a Funnel-shaped structure that opens into the nose and mouth anteriorly and joins below with the larynx b Composed of the nasopharynx oropharynx and laryngopharynx Nasopharynx and nasal passages a Contain the turbinates i Turbinates Three curved bone shelves inside each nasal passage that force inhaled air to flow in a steady pattern across the largest possible surface of the cilia and tissue that controls climate b Warm filter and humidify air as a person breathes c The nasal mucosa is the mucous membrane that lines the nasal cavity d Olfactory receptors located in the epithelium are responsible for recognizing odors Air enters through the mouth more rapidly and directly a Less moist than air that enters through the nose b Air inhaled through the mouth passes through the oropharynx i Oropharynx is separated from nasopharynx by the hard palate anteriorly soft palate posteriorly c Once through the nasopharynx and oropharynx air then enters the laryngopharynx hypopharynx i Laryngopharynx Inferiormost passage of the upper airway The esophagus and trachea are at the bottom of the pharynx a Esophagus behind and trachea windpipe in front b Food and liquids enter the pharynx and pass into the esophagus i Esophagus carries them to the stomach c Air and other gases enter the trachea and go to the lungs Epiglottis a Thin leaf-shaped valve that protects the opening of the trachea b Allows air but not food to enter the trachea under normal circumstances Air moves past the epiglottis into the larynx and the trachea The glottis glottic opening is the space between the vocal cords where air enters the trachea C Lower airway Adam s apple thyroid cartilage a Easily seen in middle of front of neck b Actually the anterior part of the larynx c Tiny muscles open and close the vocal cords and control tension on them which results in sound as air is forced past the vocal cords Immediately below is the palpable cricoid cartilage Cricothyroid membrane a Located between thyroid and cricoid cartilage b Can be felt as a depression in the midline of the neck just inferior to thyroid cartilage Below the cricoid cartilage is the trachea The trachea extends to the thoracic cavity a Splits and branches into the right and left mainstem bronchi where air enters the lungs Trachea a Approximately long b Semirigid enclosed air tube made up of rings of cartilage that are open in the back c Enables food to pass through the esophagus Esophagus lies right behind the trachea a Rings of cartilage keep the trachea from collapsing when air moves into and out of the lungs Bronchial tree Composed of airways leading from the trachea to the alveoli a Branches begin with the right and left primary bronchi near the level of the fifth thoracic vertebra b Each primary bronchus divides into a secondary bronchus tertiary bronchi and even finer tubes At the fifth thoracic vertebra trachea branches into right and left mainstem bronchi at the carnia a Carnia A projection of the lowest portion of the tracheal cartilage Air enters the lungs through mainstem bronchi a Hilum Point of entry for the bronchi vessels and nerves into each lung b The mainstem bronchi divide into the secondary bronchi each one going to a separate lobe of the lung Secondary bronchi branch into tertiary bronchi a Bronchioles are small subdivisions of the bronchi b Each bronchiole divides to form alveolar ducts c Each alveolar duct ends in clusters known as alveoli where gas exchange takes place d Pulmonary surfactant found in the alveoli reduces surface tension e Alveolocapillary membrane lies between the alveolus and the capillaries which cover the alveoli f Respiratory exchange between the lung and blood vessels occurs in the alveoli at the alveolocapillary membrane Lungs a Primary organs of breathing b Right lung contains three lobes lower middle and upper c Left lung contains two lobes lower and upper d Surrounded by a membrane of connective tissue pleura e Visceral pleura Pleural membrane that covers the lungs and folds back to become parietal pleura f Pleural space is potential space that can be created between the visceral and parietal pleura as a result of disease or trauma i Normally the two membranes are close together no space exists ii Fluid or air may accumulate potentially causing respiratory problems g Lungs receive blood in two ways i Deoxygenated blood flows from the right ventricle via the pulmonary arteries and capillaries ii Flows through pulmonary capillaries at the alveoli blood is reoxygenated and returns to the heart via the pulmonary veins h Bronchial arteries branch off of the thoracic aorta and supply the lung tissues with blood i Deoxygenated blood returns to the heart via the bronchial veins i Peripherally in the lungs venous blood from the bronchi enters the pulmonary veins returning with oxygenated blood from the alveoli D Muscles of breathing Primary muscle is the diaphragm a Contraction of the diaphragm and chest wall muscles allows air to be drawn into the lungs b Dome-shaped muscle that divides the thorax from the abdomen c Acts like a voluntary muscle when you take a deep breath cough or hold your breath d Performs an automatic function breathing continuously during sleep and at all other times e Behaves like an involuntary muscle Internal and external intercostal muscles the abdominal muscles and the pectoral muscles are involved in breathing Diaphragm contracts it moves down slightly enlarging the thoracic cage from top to bottom External intercostal muscles contract they move the ribs up and out Combined actions enlarge the chest cavity in all dimensions and air rushes into the lungs During exhalation the diaphragm and the intercostal muscles relax all dimensions of the thorax decrease and air in the lungs is compressed and pushed out through the trachea Forceful exhalation involves contraction of the posterior internal intercostals muscles pulling the ribs and sternum downward and inward to further increase the pressure in the lungs Typically breathing is easy and requires little muscular effort If resistance in the airway were to increase the abdominal and pectoral muscles assist the diaphragm in breathing XVI The Respiratory System Physiology A The primary function of the respiratory system is to exchange gases at the alveolocapillary membrane or conduct respiration B Oxygen is essential for the body to function The amount of oxygen in inspired air is approximately C Ventilation is the process of moving air in and out of lungs A patient receives a concentration of oxygen with each ventilation provided by rescue personnel D Respiration At the alveolocapillary exchange surface oxygen moves across the membrane and into the capillaries where it attaches to the hemoglobin Oxygenated blood enters the left side of the heart and is pumped to the tissues Oxygen is exchanged from the red blood cells to the tissues for carbon dioxide Venous blood returns to the right side of the heart and the pulmonary capillary bed There are many alveoli so a large surface area exists for respiratory exchange to occur The amount of surface area available for ventilation V is matched with the amount of blood flowing in the alveoli available for gas exchange also called perfusion Q a Disturbances in this balance are known as V Q mismatch and are the result of severe illness or injury Chemical control of breathing a The respiratory center in the brainstem controls breathing i Well protected deep within the skull ii Nerves in this area act as sensors for carbon dioxide levels in the blood and spinal fluid iii The brain automatically controls breathing if the level of carbon dioxide or oxygen in the arterial blood is too high or too low a Adjustments can be made in one breath which is why you cannot hold your breath or breath rapidly or deeply indefinitely b Changing levels of carbon dioxide in the blood affect pH c Respiratory center adjusts ventilation accordingly b A less sensitive backup system to control respiration is the hypoxic drive i Sensors in the walls of the aorta note oxygen levels c Buffer systems i Buffers absorb hydrogen ions when they are in excess and donate hydrogen ions when they are depleted ii Buffer systems act as rapid defenses for acid-base changes iii H BufferH Buffer iv Respiratory system and the renal system work in conjunction with the bicarbonate buffer to maintain homeostasis v Excess acid can be expelled as carbon dioxide from the lungs and slowing respirations will increase carbon dioxide in alkalotic states vi Renal system regulates pH by filtering out more hydrogen and retaining bicarbonate in acidotic states and the reverse in alkalotic states The nervous system control of breathing a Two main portions of the medulla control breathing The dorsal respiratory group DRG and the ventral respiratory group VRG b DRG responsible for initiating inspiration c Pons another area within the brainstem helps regulate the DRG activities i Pneumotaxic pontine center located in the superior portion of the pons helps shut off the DRG resulting in shorter faster respirations ii The apneustic center located in the inferior portion of the pons stimulates the DRG resulting in longer slower respirations d The two areas of the medulla and the two areas of the pons work together to get the right amount of air when need e The VRG pneumotaxic center and apneustic center are involved in changing the depth of inspiration expiration or both f Hering-Breuer reflex stops the VRG pneumotaxic center and apneustic centers from accidentally causing lung trauma g Refer to Table for a list nervous system functions regarding respirations E Ventilation Tidal volume The amount of air moved in a single breath Inspiratory reserve volume The deepest breath you can take after a normal breath Expiratory reserve volume The maximum amount of air you can forcibly breathe out after a normal breath Residual volume Gas that remains in the lungs to keep them open does not move during ventilation Vital capacity The amount of air moved with maximum inspiration and expiration Dead space The portion of the respiratory system that has no alveoli and therefore little or no exchange of gas between air and blood occurs a Mouth trachea bronchi and bronchioles are considered dead space b Gas must fill the device before it can be moved into the patient Minute volume a Provides a more accurate determination of effective ventilation b Also called minute ventilation or minute respiratory volume MRV c Minute volume respiratory rate tidal volume d Helps determine how deeply a patient is breathing F Characteristics of normal breathing Should appear easy not labored Smooth flow of air moving into and out of the lungs Adequate rate and depth tidal volume Regular rhythm pattern of inhalation and exhalation Audible breath sounds on both sides of the chest Regular rise-and-fall movement on both sides of the chest Movement of the abdomen Silent and effortless G Inadequate breathing patterns in adults Labored breathing Rate lower than breaths min or higher than breaths min Muscle retractions above the clavicles between the ribs below the rib cage Pale or cyanotic blue skin Cool damp clammy skin Tripod position a A person in the tripod position sits leaning forward on outstretched arms with the head and chin thrust slightly forward Agonal gasps a Patient may appear to be breathing after normal respiration stops b Occasional gasping breaths c Occur when the respiratory center in the brain continues to send signals to the breathing muscles d Assist ventilations of patients with agonal gasps XVII The Circulatory System Anatomy A Consists of the heart and a complex arrangement of connected tubes Includes the arteries arterioles capillaries venules and veins B Another name for this system is the cardiovascular heart blood vessels system C The circulatory system is entirely closed D Two circuits in the body Systemic circulation a Travels throughout the body b Carries oxygen-rich blood from left ventricle through body back to right ventricle c As blood passes through tissues and organs it i Gives up oxygen and nutrients ii Absorbs wastes and carbon dioxide d Cellular wastes are eliminated when blood goes through liver and kidneys Pulmonary circulation travels only between the heart and lungs a Oxygen-poor blood goes from right ventricle through lungs back to left atrium b As blood passes through lungs it gains oxygen and loses carbon dioxide E The heart Location and major structures of the heart a Muscular organ that pumps blood throughout the body b The heart muscle is called the myocardium c Located behind the sternum d About the size of the closed fist of the person it belongs to e About two thirds of the heart lies in the left part of the mediastinum the area between the lungs that also contains the great vessels f The pericardium is the membrane surrounding the heart g Three layers composing the wall of the heart are the outer epicardium middle myocardium and inner endocardium i Epicardium protects the heart by reducing friction ii Myocardium is made mostly of cardiac muscle tissue iii The endocardium is made up of epithelium and connective tissue and is the interior lining of the heart iv Also contains specialized cardiac muscle fibers known as Purkinje fibers h The heart has four chambers two atria upper chambers and two ventricles lower chambers i Each side of the heart contains one atrium and one ventricle ii The interatrial septum separates the two atria iii The interventricular septum separates the right and left ventricles j The atria receive blood returned to the heart k The ventricles pump blood out of the heart l Blood enters the right atrium via the superior and inferior venae cavae and the coronary sinus which consists of veins that collect blood returning from the walls of the heart m Blood from four pulmonary veins enters the left atrium n The fossa ovalis is a depression between right and left atria that represents the former location of the foramen ovale the opening between the two atria that is present in the fetus Valves of the heart a Blood passing from the atria to the ventricles flows through one of two atrioventricular valves i The tricuspid valve separates the right atrium from the right ventricle ii The mitral valve a bicuspid valve separates the left atrium from the left ventricle iii Valves consist of flaps cusps b Papillary muscles attach to the ventricles and send small muscular strands chordae tendineae to the cusps i When the papillary muscle contracts these strands tighten preventing backflow of blood through the valves from the ventricles to the atria c Two semilunar valves divide the heart from the aorta and the pulmonary artery i Pulmonary valve Regulates blood flow from the right ventricle to the pulmonary artery ii Aortic valve Regulates blood flow from the left ventricle to the aorta iii Not attached to papillary muscles iv When they close they prevent backflow from the aorta and pulmonary artery into the left and right ventricles respectively Blood flow within the heart a Deoxygenated blood returns to the right atrium via two large veins the superior vena cava and inferior vena cava i Blood flows from upper part via superior vena cava from lower part via inferior vena cava ii Inferior vena cava is larger b Blood flows from right atrium through tricuspid valve to right ventricle c Blood is pumped from right ventricle to pulmonic valve into pulmonary artery and lungs d Freshly oxygenated blood returns to the left atrium through pulmonary veins e Blood flows through the mitral valve into the left ventricle f The left ventricle pumps oxygenated blood into the aorta the body s largest artery and then to the entire body i The left ventricle is the strongest and largest of the four cardiac chambers because it is responsible for pumping blood through blood vessels throughout the body Heart sounds a Created by contraction and relaxation of the heart and flow of blood b Heard during auscultation with a stethoscope c Normal heart sound lub-DUB d S and S are normal sounds S and S are often not e Other abnormal sounds include murmurs bruits clicks and snaps i A murmur is an abnormal whooshing-like sound heard over the heart that indicates turbulent blood flow through the heart valves ii A bruit is an abnormal whooshing-like sound that often indicates localized atherosclerotic disease plaque formation in the arteries The electrical conduction system a Electrical stimuli control the mechanical pumping action of the heart b Conduction system components i Sinoatrial SA node Site of origin of the electrical impulse ii Atrioventricular AV node iii Bundle of His iv Right and left bundle branches v Purkinje fibers Regulation of heart function a Autonomic nervous system endocrine hormones and heart tissue control i Rate of contraction chronotropic state ii Rate of electrical conduction dromotropic state iii Strength of contraction inotropic state b Baroreceptors respond to changes in pressure i Located in the blood vessels kidneys brain and heart c Chemoreceptors sense changes in chemical composition of blood d Stimulation of receptors often causes activation of either the parasympathetic or sympathetic branches of the autonomic nervous system affecting both the heart rate and the strength of heart muscle contraction contractility e Parasympathetic stimulation slows the heart rate f Sympathetic stimulation has alpha effects or beta effects depending on which nerve receptor is stimulated i Alpha effects result in vasoconstriction ii Beta effects result in increased inotropic dromotropic and chronotropic states iii Epinephrine has a greater stimulatory effect on beta-receptors iv Norepinephrine has predominant stimulatory actions on alpha-receptors v Epinephrine and norepinephrine are also referred to as catecholamines The cardiac cycle a Process that creates the pumping of the heart b Systole i Contraction of ventricular mass ii Pumping of blood into the systemic circulation c Diastole i Relaxation phase of the cycle d Pulse pressure systolic pressure diastolic pressure e Afterload is the pressure in the aorta against which the left ventricle pumps blood f Stroke volume SV is the amount of blood ejected per contraction g Cardiac output stroke volume heart rate i Factors that influence heart rate stroke volume or both will affect cardiac output and thus oxygen delivery ii Starling s law Cardiac muscle when stretched contracts with greater force iii Ejection fraction Amount of blood ejected from ventricle usually the same as amount of blood returned to heart iv Preload Pressure under which a ventricle fills F The vascular system Arteries carry blood away from the heart Veins carry blood back to the heart Arteries branch into arterioles Arterioles divide into capillaries a Capillaries Microscopic thin-walled blood vessels b Oxygen and nutrients go from capillaries to cells c Carbon dioxide and waste products go from cells into capillaries by diffusion d Deoxygenated blood is returned to the heart starting with the capillaries Capillaries enlarge to form venules Venules merge to form veins a Veins empty into heart and process starts again Walls of the blood vessels are composed of three layers a The smooth thin inner lining is the tunica intima or endothelium b The middle layer or tunica media is composed of elastic tissue and smooth muscle cells c The outer layer consisting of elastic and fibrous connective tissue is the tunica adventitia d Total volume of all vessels in the body forms a large dynamic container i If baroreceptors in the central circulation detect a drop in pressure the blood vessels constrict to shrink the size of the container proportionally to maintain homeostasis ii In a process known as shunting the autonomic nervous system also changes the distribution of blood by constricting peripheral blood vessels to a greater degree than those supplying the vital organs This is a hallmark sign of shock Circulation to the heart a Supplied by the right and left coronary arteries which arise from the aorta b Receive their blood supply during the diastolic phase c Right coronary artery divides and supplies blood to the walls of the right atrium and ventricle a portion of the inferior part of the left ventricle and portions of the conduction system the sinus and AV node d Left coronary artery is the largest and shortest of the myocardial blood vessels and divides into the left anterior descending LAD artery and the circumflex coronary arteries supplying blood to most of the left ventricle the intraventricular septum and at times the AV node Pulmonary circulation a Carries blood from the right side of the heart to the lungs b Carries blood back to the left side of heart c Deoxygenated blood from the right ventricle is pumped through the pulmonic valve into the pulmonary artery d This artery rapidly divides into the right and left pulmonary arteries i These arteries transport the blood to the right and left lungs ii Inside the lungs the arteries branch becoming smaller and smaller e At the level of the capillary waste products are exchanged and the blood is reoxygenated i Reoxygenated blood travels through venules into the pulmonary veins The four pulmonary veins empty into the left atrium two from each lung Systemic arterial circulation a Oxygenated blood leaves the heart and enters the aorta b The aorta distributes blood to all parts of the body c Ascending aorta Arises from left ventricle i Three major arteries arise from the aortic arch the brachiocephalic innominate artery the left common carotid artery and the left subclavian artery d Descending aorta Longest portion of aorta extends through thorax and abdomen into the pelvis i Divides into the two common iliac arteries which further divide into the internal and external iliac arteries e Head and neck i Brachiocephalic artery divides into the right common carotid artery and the right subclavian artery ii Transporting blood to the head and neck each common carotid artery branches at the mandible into the internal and external carotid arteries iii Division point is called the carotid bifurcation f Upper extremity i The subclavian artery supplies blood to the brain neck anterior chest wall and shoulder ii At the shoulder joint it becomes the axillary artery then the brachial artery below the head of the humerus g Thoracic aorta i Visceral arteries supply blood to the thoracic organs ii Parietal arteries supply blood to the thoracic wall iii Intercostal arteries run along the ribs and supply the chest wall h Abdominal aorta i Visceral arteries are subdivided into paired and nonpaired arteries ii Three major unpaired branches of the abdominal aorta s visceral arteries include the celiac trunk the superior mesenteric and the inferior mesenteric arteries i Pelvis and lower extremity i Two common iliac arteries divide into the internal iliac arteries ii The external iliac arteries become the femoral arteries iii Femoral artery becomes the popliteal artery in the lower thigh which then branches into the anterior tibial posterior tibial and peroneal arteries iv At the foot the anterior tibial artery becomes the dorsalis pedis artery v Plantar arteries arise from the posterior tibial artery Systemic venous circulation a Drains deoxygenated blood from the body to the heart b As a rule veins accompany major arteries and often have same names c Head and neck i Two major veins that drain the head and neck of blood are called the external and internal jugular veins ii Venous sinuses are the primary means of venous drainage from the brain into the internal jugular vein iii External and internal jugular veins join the subclavian veins to form the brachiocephalic veins which drain into the superior vena cava d Upper extremity i Major veins of the arm are the basilic vein and the cephalic vein ii Combine to form the axillary vein which drains into the subclavian vein e Thorax i Drainage begins at the anterior and posterior intercostal veins ii Empties into the azygos vein on the right and the hemiazygos vein on the left iii With right and left brachiocephalic veins provide the major source of flow into the superior vena cava f Abdomen and pelvis i All venous drainage from the lower part of the body passes through the inferior vena cava ii Hepatic portal system is a specialized part of the venous system that drains blood from the liver stomach intestines and spleen iii Blood from the system flows first through the liver where blood collects in sinusoids iv Drains into the hepatic veins which join the inferior vena cava g Lower extremity i Longest vein in the body is the great saphenous vein which drains the foot leg and thigh ii Originates over the dorsal and medial side of the foot ascending the leg and thigh iii Empties into the femoral vein which then drains into the external iliac vein iv Anterior and posterior tibial veins unite at the knee to form the popliteal vein which ascends through the thigh becoming the femoral vein G Blood composition Substance pumped by the heart through arteries veins and capillaries Blood consists of plasma and formed elements or cells suspended in the plasma Purpose of blood is to carry oxygen and nutrients to the tissues and cell waste products away from them Formed elements are crucial to many other body functions such as fighting infection Plasma Water straw-colored fluid that accounts for over half the total blood volume Components of plasma The remaining is chemicals minerals and nutrients a Water Constitutes b Proteins Constitutes i Albumins a Majority of plasma proteins b Control movement of water into and out of circulation by regulating oncotic pressure ii Globulins a Antibodies made by liver b Around of plasma proteins iii Fibrinogen a Important for blood coagulations b About of plasma proteins c Oxygen Almost all of it is bound to hemoglobin little is dissolved here d Carbon dioxide Transported as bicarbonate here e Nitrogen Air you breathe is mostly nitrogen it is dissolved in plasma f Nutrients Fuel for the cells g Cellular wastes lactic acid carbon dioxide etc h Others hormones etc Formed elements a Created through a process known as hematopoeisis b Begin in the bone marrow c Hematocytoblast form and gradually differentiate into one of the blood components i Either reticulocytes the precursors to red blood cells RBCs or other formed elements Red blood cells a Carry oxygen to tissues b Known as erythrocytes they are the most numerous of the formed elements c Contain hemoglobin a protein which carries the oxygen by binding to it d Erythropoiesis is the ongoing process by which red blood cells are made e Red blood cells have a finite life span of days f Some components of hemoglobin such as the protein globin and iron are recycled by the body g The part of hemoglobin that is not recycled is converted to bilirubin which undergoes further metabolism in the liver h Antigens on the surface of red blood cells determine a person s ABO and Rh blood group i Antibodies are proteins in the plasma that react with antigens j During hypoxia or low levels of oxygen concentration in the blood the kidneys produce erythropoietin which stimulates the production of erythroblasts in the bone marrow White blood cells a Also known as leukocytes b Fight infection c Leave blood vessels by a process known as diapedesis to get to tissues where they are needed d Varieties i Granulocytes neutrophils eosinophils basophils ii Agranulocytes lymphocytes monocytes e Neutrophils the most common type of granulocyte destroy bacteria antigen-antibody complexes and foreign matter f Eosinophils function in the body s allergic response g Basophils the least common type of granulocyte are involved in both allergic and inflammatory reactions i Contain large amounts of histamine and heparin h Lymphocytes originate in the bone marrow but migrate through the blood to the lymphatic tissues i Most are located in the lymph nodes spleen tonsils lymph nodules and thymus i Monocytes and macrophages are one of the first lines of defense in the inflammatory process j Monocytes engulf microbes and digest them in a process called phagocytosis k Unlike short-lived neutrophils monocytes mature into long-lived macrophages Platelets and blood clotting a Small cells in blood that are necessary for chemical reactions to occur that form a clot i Clotting begins with platelets clumping together b A series of events occurs to form a clot including hemostasis cessation of bleeding c Clotting is a chain reaction stimulated by the release of a chemical called thromboplastin from injured cells lining damaged blood vessels d Thromboplastin causes the inactive plasma enzyme prothrombin to be converted into its active form thrombin e Thrombin also activates another blood protein fibrinogen which is converted into fibrin f Fibrin are long branching fibers that produce a weblike network in the wall of the damaged blood vessel and binds to the platelet plug stopping the flow of blood g Body has two systems to counterbalance clotting i One the fibrinolytic system lyses or disrupts clots that already have formed ii The main steps are the activation of tissue plasminogen activator t-PA which then converts plasminogen to plasmin iii The fibrinolytic system and the body s own anticoagulants attempt to provide a balance between clotting and bleeding XVIII The Circulatory System Physiology A The pulse is created by blood pumping out the left ventricle into major arteries Pulses are palpated most easily at the neck wrist or groin where the larger arteries are near the skin B Blood pressure is the pressure that blood exerts against artery walls Sphygmomanometer measures high and low points of wave Systole and diastole are the phases that occur when the left ventricle contracts and when the ventricle relaxes respectively C Systemic vascular resistance SVR is the state of how dilated or constricted the blood vessels are Resistance to blood flow within blood vessels except pulmonary vessels Important relationship between the size of the vessels and shock D The average adult has about L of blood Children have to L and infants have mL E Normal circulation in adults The circulatory system normally adjusts and readjusts automatically a of capacity of arteries veins and capillaries should hold of blood at that moment b Vessels are never fully dilated or constricted c Size of arteries and veins is controlled by the nervous system to maintain normal blood pressure d Feedback mechanisms maintain systems so the body receives adequate circulation without overtaxing any part of the system Perfusion is circulation of blood in an organ or tissue in adequate amounts to meet the cell s current needs a Blood enters through arteries and leaves through veins Loss of normal blood pressure indicates that blood is not circulating effectively to every organ in the body a Note Good blood pressure doesn t necessarily mean that blood is reaching all parts of the body Loss of blood pressure can have many causes but it always has the same results a Cells tissues and organs are no longer adequately perfused or supplied with oxygen and food b As a result they may die Shock hypoperfusion is the state of inadequate circulation involving the entire body F Inadequate circulation in adults Heart arteries and veins automatically adjust to lower blood volume when patient loses a small amount of blood Heart attempts to maintain adequate pressure throughout circulatory system by constricting vessels to provide smaller volume to fill a Happens within minutes of blood loss Heart pumps more rapidly to circulate lower amount of blood more efficiently Pulse increases to keep cardiac output constant as pressure falls If blood loss is too great and adjustments fail patient goes into shock G The distribution of blood of blood is in the heart arteries and capillaries a High-pressure system of blood is in the veins and venules a Low-pressure system Nutrients move from capillaries into interstitial space and into the cells a Hydrostatic pressure on arterial side of capillary is higher forcing plasma into interstitial space b Hydrostatic pressure decreases by the time the fluid reaches the venous side of the capillary Wastes move from the cells through the interstitial space into capillaries a Oncotic pressure pushes plasma and wastes back into the capillary XIX The Lymphatic System A Functions Primary function is production maintenance and distribution of lymphocytes Transports excess fluid out of interstitial spaces in tissues and return it to the bloodstream Transports lymph by passive circulation a Lymph Thin plasma-like fluid formed from interstitial or extracellular fluid that bathes the tissues of the body b Lymphatic capillaries pick up the lymph and drain it into larger vessels c Lymph circulates through body in thin-walled lymph vessels that travel close to the major arteries and veins i Like veins lymphatic vessels contain valves that limit backflow d Foreign material is filtered from the lymph in the lymph nodes i Lymph nodes Round or bean-shaped structures that are interspersed along the course of the lymph vessels e Returns to the main circulatory system via the thoracic duct i Thoracic duct One of two great lymph vessels which empties into the junction of the left subclavian vein and the left internal jugular vein f The movement of lymph is influenced by muscular activity Helps absorb fat from the digestive tract maintain fluid balance in the body and fight infection B Lymphatic vessels Only carry fluid away from the tissues a In lymphatic capillaries epithelial cells contain one-way valves that allow fluid to enter the vessel but prevent it from flowing back into the tissues Lymphatic capillaries are present in all tissues except the central nervous system bone marrow cartilage epidermis and cornea Generally fluid flows from the blood capillaries to the tissues then out of the tissue spaces into lymph capillaries To prevent tissues from becoming edematous lymph vessels absorb excess fluid and return it to the central venous circulation C The thymus Located in the thorax anterior to the aorta and posterior to the upper sternum Divided into lobules by inward extending Contain large amounts of lymphocytes including primarily inactive thymocytes Some thymocytes mature into T lymphocytes which provide immunity D The spleen Located in the upper left abdominal cavity inferior to the diaphragm and posterior and lateral to the stomach Largest lymphatic organ Unlike the lymph nodes its venous sinuses are filled with blood not lymph Via the action of macrophages and lymphocytes the spleen filters blood similarly to the way that lymph nodes filter lymph E Body defenses and fighting infection Body defenses can be divided into two general categories a Innate nonspecific i Present at birth ii Includes mechanical barriers chemical barriers natural killer cells NK cells inflammation phagocytosis fever and species resistance b Adaptive specific i More precise and targets specific pathogens to provide immunity ii Specialized lymphocytes recognize foreign molecules and act against them Innate and adaptive defense mechanisms work together to fight infection a Innate defenses act more rapidly than adaptive defenses b Specific defenses depend on the activity of lymphocytes F Innate nonspecific defenses Mechanical barriers physical barriers are the first line of defense a Include the skin and mucous membranes lining the respiratory digestive urinary basement membranes and reproductive passageways b Also hair sweat and mucus Chemical barriers provided by enzymes and other chemical substances in body fluids a Includes pepsin and hydrochloric acid in the stomach tears lysozyme in tears saliva breast milk and mucus salt in perspiration and interferons hormone-like peptides b Binds to uninfected cells and stimulates them to make protective proteins and complement a group of proteins in plasma and other body fluids that interact to cause inflammation and phagocytic activities Fever is the elevation of body temperature that reduces iron in the blood inhibits bacterial and fungal reproduction and causes increased phagocytosis Inflammation is tissue response to injury or infection that may include redness swelling heat and pain infected cells attract white blood cells which engulf them Immunologic surveillance is the constant monitoring recognizing and destruction of abnormal cells by natural killer NK cells in peripheral tissues a NK cells defend the body against cancer cells and viruses Langerhans cells antigen-presenting cells detect process and present foreign materials or germs to other parts of the immune system stimulating an immune response Phagocytosis involves neutrophils and monocytes attracted to injured tissues engulf and digest pathogens and cell debris a Mononuclear phagocytic system removes foreign particles from the lymph and blood via various phagocytic cells Species resistance refers to someone being resistant to certain diseases G Immunity specific defenses Known as the third line of defense Resistance to specific pathogens or their toxins and metabolic by products Lymphocytes and macrophages recognize and remember certain proteins and large molecules as being self and foreign molecules as nonself Haptens combine with larger more complex molecules to elicit an immune response T lymphocytes T cells make up between and of circulated blood lymphocytes B lymphocytes B cells make up between and of the circulating lymphocytes Cellular immune response involves T cells attaching to foreign antigen-bearing cells such as bacterial cells Humoral immune response involves B cells dividing and differentiating into plasma cells producing antibodies immunoglobulins that react to destroy antigens or antigen-containing particles Major histocompatibility complex MHC antigens help T cells recognize foreign antigens a Helper T cells contact displayed foreign antigens and if the antigen combines with the helper T cell s antigen receptors it becomes activated and stimulates a B cell to produce antibodies specific for the displayed antigen Cytotoxic T cell recognizes and combines with foreign antigens displayed on cell surfaces near certain MHC proteins common with cancer cells or virally infected cells a Some T cells act as memory cells dividing to yield more cytotoxic T cells and helper T cells when reexposed to the same antigen B cells may activate when encountering an antigen whose shape fits the B cell s antigen receptor shape but some B cell s clones differentiate into more memory cells and other B cell clones differentiate into antibody-secreting plasma cells which can combine with their corresponding foreign antigens and react against them Refer to Tables and for summaries of B and T cell characteristics and antibody production activities respectively Antibodies are soluble proteins making up the gamma globulin part of the plasma proteins a Immunoglobulin G IgG is found in plasma and tissue fluids IgG is effective against bacteria viruses and toxins and activates complement b Immunoglobulin A IgA is found in exocrine gland secretions breast milk tears nasal fluid gastric juice intestinal juice bile and urine c Immunoglobulin M IgM is composed of five single molecules found together and is the first antibody to be produced in response to infection d Immunoglobulin D IgD is found on the surfaces of most B cells and is important in the activation of B cells e Immunoglobulin E IgE attaches to mast cells and basophils and is involved in allergic reactions Antibodies commonly attack antigens directly activate complement or stimulate inflammation a Combine with antigens causing clumping agglutination or forming insoluble substances precipitation and then phagocytosis can occur more easily Some IgM or IgG antibodies combine with antigens and trigger many reactions that lead to the activation of the complement proteins including a Coating the antigen antibody complexes opsonization b Attracting macrophages and neutrophils chemotaxis c Making the complexes more susceptible to phagocytosis d Clumping antigen-bearing cells e Rupturing foreign cell membranes lysis f Altering viral molecular structures to make them harmless A primary immune response which continues for several weeks constitutes activation of B or T cells plasma cells releasing IgM into the lymph followed by IgG After primary immune response detectable concentrations of antibodies appear in the blood plasma usually to days after exposure to antigens and a secondary immune response which can last a long time can then occur within to days Adaptive acquired immunity can be caused by natural events or by administration oral or injected of suspensions of killed or weakened pathogens or their molecules Vaccines cause patients to develop artificially acquired active immunity Injection of gamma globulin antiserum provides artificially acquired passive immunity after exposure to a disease-causing organism Antibodies passed from maternal blood to the fetus during pregnancy give the fetus limited immunity months to year after birth against pathogens that the mother is immune to Allergic response is an immune response to a nonharmful substance or allergen Classifications of allergic responses are a Delayed-reaction allergy results from repeated exposure and takes about hours to occur b Immediate-reaction allergy affects people with inherited tendencies to overproduce IgE antibodies because of certain antigens and takes only a few minutes to occur c Transplantation and tissue rejection is the result of the receiving patient s immune system recognizing the transplanted part as foreign and attempting to destroy it d Autoimmunity or attack against self H The effects of aging on the lymphatic system and immunity As a person ages the lymphatic system becomes less effective at fighting disease and results in lowered immunity With decreased immunity tumor cells are not eliminated as effectively and cancer rates increase with age XX The Nervous System Anatomy and Physiology A Perhaps most complex organ system in the body B Components Brain Spinal cord Thousands of nerves a Allow every part of the body to communicate C Responsible for fundamental functions such as breathing pulse rate and blood pressure D Nervous system is divided into the central nervous system CNS and the peripheral nervous system PNS Somatic nervous system is the part of the peripheral nervous system that regulates activities over which there is voluntary control Autonomic nervous system ANS controls the many body functions that occur without voluntary control Neural tissue conducts electrical impulses between the brain and the rest of the body a Contains nerve cells or neurons projections called axons and dendrites that make connections between adjacent cells and neuroglia which are supporting cells Neuroglia provide a supporting skeleton for neural tissue isolate and protect the cell membranes of neurons regulate the composition of interstitial fluid defend neural tissue from pathogens and aid in the repair of injury a Neuroglia can divide whereas most neurons cannot b Classifications of neuroglia cells include i Astrocytes are usually found between neurons and blood vessels ii Ependymal cells cover specialized brain parts form inner linings enclosing spaces inside the brain and spinal cord and secrete cerebrospinal fluid iii Microglial cells are found throughout the CNS and phagocytize bacterial cells and cellular debris iv Oligodendrocytes are found along nerve fibers and provide insulating layers of myelin around axons within the brain and spinal cord In unmyelinated axons action potential electrical signals propagate along the entire axon membrane Myelinated nerves are surrounded by a myelin sheath manufactured by Schwann cells Narrow gaps between the Schwann cells are known as nodes of Ranvier In myelinated nerves the action potential jumps between these regions in a process called saltatory conduction which increases the speed of transmission of the impulse Bundles of myelinated nerves are referred to as white matter A variety of neurons is as follows a Sensory neurons afferent neurons carry nerve impulses from the peripheral body parts into the brain or spinal cord b Interneurons association or internuncial neurons are within the brain and spinal cord the cell bodies of some form masses called nuclei which are similar to ganglia c Motor neurons efferent neurons carry impulses out of the brain or spinal cord to effectors Classes of neurons are as follows a Multipolar neurons make up most of the neurons whose cell bodies lie within the brain or spinal cord i They have many processes that arise from their cell bodies with only one being an axon and the rest being dendrites b Bipolar neurons exist in specialized parts of the eyes nose and ears i They have only two processes arising from their cell bodies with one being an axon and the rest are dendrites c Unipolar neurons often aggregate in specialized ganglia outside the brain and spinal cord i They have a single process extending from the cell body that divides into two branches that function more like a single axon the peripheral process associated with dendrites near a peripheral body part and the central process enters the brain or spinal cord Gap between nerve cells is the synapse Presynaptic terminal is at one end of a nerve Synaptic cleft is the space between neurons Postsynaptic terminal is opposite the presynaptic terminal and across the synaptic cleft Electrical impulses travel down the nerve and trigger the release of neurotransmitters from the presynaptic terminal Neurotransmitters are contained within synaptic vesicles and released into the synaptic cleft Electrical reaction passes through the neuron to the next synapse and the process is repeated The nervous system is divided into the central nervous system CNS the peripheral nervous system PNS and the autonomic nervous system ANS E The central nervous system CNS Brain a Controlling organ of body center of consciousness b Main components i Cerebrum Gray matter controls activities on opposite side of body ii Corpus callosum is a deep ridge of nerve fibers that connects the two cerebral hemispheres iii Lobes of the cerebral cortex include the frontal lobe the parietal lobe the temporal lobe and the occipital lobe iv Cerebellum Little brain located under the cerebrum coordinates various activities including body movements v Brainstem Controlling center for cardiac respiratory and other basic body functions comprises the midbrain the pons and the medulla oblongata the reticular activating center keeps you conscious vi Ventricles Interconnected cavities within the cerebral hemispheres and brainstem continuous with the spinal cord s central canal and contains cerebrospinal fluid CSF vii CSF surrounds the brain and spinal cord maintaining a stable ionic concentration and protecting CNS structures c Refer to Table for a list of the major portions of the nervous system and their functions Spinal cord a Is an extension of the brainstem b Exits the skull through the foramen magnum c Encased within the spinal canal down to the level of the second lumbar vertebra d Carries information to and from the brain e Nerve fibers are arranged in specific bundles within the spinal cord to carry the messages