Human Anatomy and Physiology Critical Thinking Questions.docx

CRITICAL THINKING QUESTIONS Chapter 1 In some states, death is defined as ‘‘The cessation of the vital functions of the body or the cessation of the heartbeat and respirations.’’ Definitions of death are related to the characteristics of life in that death is characterized by an absence of brain waves, reflexes, responsiveness, receptivity, spontaneous muscular movements, blood pressure, pulse, and spontaneous respirations. Treatment of body temperature—increased fluid intake, hypothermia blanket, antipyretic medications, antibiotics if fever is due to an infection, rest, and maintaining nutritional intake. Blood oxygen—oral tracheal suction to keep airway open, administering oxygen. Water content—increased fluid intake, administering intravenous fluid, controlling room temperature and humidity. The individual with the tumor in the dorsal cavity would probably develop symptoms first. Since the dorsal cavity is smaller, the tumor would exert pressure against the brain or spinal cord, causing symptoms of visual disturbances, headaches, behavioral changes, disequilibrium, disturbances in gait, seizures, incoordination, or weakness in the extremities. The organs in the umbilical region that could be the source of pain include the small intestine (obstruction), pancreas (pancreatitis), abdominal aorta (aneurysm), transverse colon (diverticulitis), or a distended urinary bladder. An unconscious person would need: oral tracheal suctioning (to keep the airway open and administer oxygen); nasogastric, gastric, or intravenous feedings; urinary catheter (for urine collection); turning in bed (to prevent decubitus ulcers, or bedsores); elastic stockings (to prevent blood clots and thrombophlebitis); stool softeners or suppositories; range-of-motion exercises to the extremities; and possibly a hypothermia or hyperthermia blanket to maintain body temperature. Ultrasonography would be preferable since it does not use radiation, but uses very high frequency sound waves. Chapter 2 Examples of acidic substances: vinegar (acetic acid); aspirin (acetylsalicylic acid); rust remover (oxalic acid); toilet bowl cleaner (muriatic acid); and automobile battery fluid (sulfuric acid). Examples of basic substances: ammonia; lye; drain and oven cleaner (sodium hydroxide); milk of magnesia (magnesium hydroxide); and antacids (sodium bicarbonate). Examples of acidic foods: meat (protein in general); whole wheat (grain in general); eggs; cheese; cranberries; plums; cola drinks; and tomatoes. Examples of basic foods: milk (fresh); vegetables; raisins; apricots; and nuts. Examples of sources of saturated fats: butter; shortening; red meats; poultry; egg yolk; cheese; ice cream; whole milk; cream; seafood; crackers made with palm or coconut oil; and lard. Examples of sources of unsaturated fats: olives; olive oil; margarine (from corn oil); foods prepared with cottonseed, peanut, soybean, or safflower oil. Radiation therapy uses precisely controlled doses of radioactivity that are targeted to irradiate only the tumor. A patient subjected to CT scanning does not become a radiation source. Although radiation therapy may damage tissues, the benefits derived from medical uses are thought to outweigh the health risks. The body utilizes carbohydrates to provide energy for metabolic reactions. Proteins are important in that they comprise structural components of tissues such as collagen, muscle fibers, cell membranes, elastin, and keratin, and also have functional roles as antibodies, enzymes, and certain hormones. Clinical laboratory tests: Serum sodium; potassium; chloride; carbon dioxide; glucose; BUN (blood urea nitrogen); acid phosphatase; alkaline phosphatase; calcium; cholesterol; triglycerides; iron; total protein; cardiac enzymes (CPK, SGOT, LDH); liver enzymes (SGPT); arterial blood gases; and urine (pH, glucose, ketones, blood protein). The symptoms of many inherited diseases stem from protein malfunction because genes encode proteins. Chapter 3 a. Osmosis. The hypertonic drug solution would cause water to leave the cells, swelling the tissues, pressing on nerves, and causing pain. b. Filtration. A low blood pressure would not result in enough hydrostatic pressure to force water and dissolved particles (glomerular filtrate) from the glomerular capillaries into the kidney tubules. c. Diffusion. Urea, an end product of protein metabolism, would need to diffuse from a higher concentration in the patient's blood to a lower concentration in the dialyzing fluid if it is to be removed from the blood. Cell membranes contain phospholipids, into which fat-soluble substances (organic solvents) would easily diffuse. White blood cells normally increase in number during an infection. Exposure to an X -ray may destroy these cells, along with their ability to phagocytose bacteria and produce antibodies against bacteria and viruses. The rhythmic beating of cilia normally aids in moving respiratory secretions up into the pharynx where they are swallowed or expectorated. If cilia are immobile, secretions remain in the lower respiratory tract where they may harbor microorganisms, resulting in infections. A phagocytic cell can surround and engulf a bacterium, taking it into the cell where enzymes decompose the bacterium. Phagocytic cells work in large numbers to destroy bacteria. a. growth—cells continually undergo mitosis, increasing their numbers; they may also increase in size; b. wound healing—cells undergo mitosis only when necessary to replace those that have been injured; c. cancer—immature, undifferentiated cells undergo uncontrolled, continued mitosis, often metastasizing, or separating from the original site of the malignancy to distant organs of the body. Enlarged lysosomes may indicate that a type of lysosomal enzyme is missing or deficient. As a result, the biochemical that the enzyme normally acts upon builds up, swelling the lysosome. Enzyme deficiencies are devastating to health. Because of a somatic mutation, a somatic cell nucleus to be used as a source of ES cells in a regenerative medicine application might be unable to support development. That is, a somatic mutation may be detrimental to the cell in which it originates and anything developing from that cell, but not in the organism in which the mutation arose. Chapter 4 Since enzymes catalyze metabolic reactions at only a specific pH, if the pH of body fluids is altered, enzymes will become denatured and cell metabolism will be altered. The individual's cells utilize glucose as their primary and most efficient source of metabolic energy. With less carbohydrate available to provide glucose, the cells would make increased use of fatty acids, glycerol, and amino acids as sources of energy. The individual's urine would have a low pH (acidic), and would contain ketone bodies. Enzymes and their associated (vitamin) coenzymes are reused in metabolic reactions. Excessive amounts of coenzymes are normally excreted. Oxygen concentration would decrease and carbon dioxide concentration would increase. The result would be a lowering of blood pH, or acidosis. Rifampin is a drug that blocks bacterial transcription by binding to RNA ploymerase, preventing the genes message from being transmitted. The student's muscle are using up oxygen rapidly, and some muscle cells revert to anaerobic respiration. Lactic acid build-up causes her pain. Glycolysis is occurring too slowly, due to a deficient or absent enzyme. As a result, the person is extremely fatigued, and mentally slow because the brain cannot obtain sufficient energy. T, C, G, C, T, A, A, C, G, T, A, C, G is the sequence of the complementary DNA strand. U, C, G, C, U, A, A, C, G, U, A, C, G is the sequence of the transcribed RNA strand. Ultraviolet light can cause mutations. Chapter 5 Cartilage and (dense) fibrous connective tissue have a limited blood supply, limiting the number of phagocytes, nutrients, and red blood cells (which carry oxygen) reaching the site, thus slowing healing. Connective tissues occur throughout the body and are associated with organs of virtually every body system. a. Respiratory tubes—coughing, sputum production, difficulty breathing (dyspnea), and fever (if respiratory infection is present). b. Digestive tract—gastric pain, vomiting, diarrhea, and nausea. a. Replacement skin would have to be made of a watertight, flat substance that did not stimulate immune rejection. b. A blood substitute would require a chemical that can carry oxygen, a substance that could clot blood, and perhaps white blood cells. c. Bone would require a substance that is hard, but could be designed to include many spaces so that it would be lightweight. d. Muscle would probably be the most difficult tissue to engineer. A synthetic polymer might be seeded with myoblasts. A source of contractility is necessary. connective tissue The replacement squamous cells cannot secrete and do not have cilia, impairing lung function Epithelial cells would be most influenced. Skeletal and cardiac muscle cells and nerve cells would be least influenced. Chapter 6 Dehydration, electrolyte imbalance, inability to regulate body temperature, susceptibility to infection, decreased ability to sense touch, and vitamin D deficiency. Environmental modifications could include: aseptic environment,; hydration through oral or intravenous routes; controlling room temperature; and balanced diet. Ability to regulate body temperature would be decreased and the infant would be susceptible to hypothermia. The superficial burn would irritate, and thus stimulate, nerve endings (pain receptors); the deeper burn would destroy them. The subcutaneous injection would be absorbed more rapidly since there are more blood vessels in subcutaneous tissue than in the intradermal area. Radiation—cool room temperature Conduction—hypothermia blanket Convection—lightweight covers and loose garments Evaporation—sponge baths with cool water Radiation—cool room temperature Exercise and hot weather raise the body temperature, which increases metabolic rate, which, in turn, results in loss of water and electrolytes through sweating. Water and fruit juices replace lost fluids and electrolytes. Melanocytes are active to different degrees in different people, accounting for differences in skin color. Skin peeling is protective because it rids the body of cells that could become cancerous. A fever is protective because it creates an environment in the body that is inhospitable to some pathogens. The epidermis (outer layer) is a layer of stratified squamous epithelium that lacks blood vessels. Chapter 7 Lead—prohibit sale and import of paint, dishes, and toys containing lead; use only unleaded gasoline; and screen for lead poisoning in schools. Radium—periodically check health workers for level of exposure to radium; avoid or minimize direct contact with patients receiving radiation therapy or radioactive implants; regularly maintain radiology equipment and provide proper training in its use; monitor homes for levels of radon gas, which is a disintegration product of radium. Strontium—exert control over atomic testing and nuclear power plant emissions. Children's bones are more flexible and resilient than those of adults; thus they are less susceptible to complete fractures. Difficulties with coordination, balance, and gait. As an individual ages, intervertebral disks become thinner and more rigid, resulting in compression fractures of the anteriorly located vertebral bodies. These events, in turn, cause the vertebral column to shorten and develop an exaggerated thoracic curvature. Rate of development—if the posterior fontanel has closed two months after birth, the sphenoid three months after birth, the mastoid twelve months after birth, and the anterior by eighteen months or two years of age, the infant is probably developing ‘‘on time.’’ Delayed closing of these fontanels may indicate slower than normal development. Intracranial pressure—Depressed or ‘‘sunken in’’ fontanels may indicate decreased intracranial pressure or dehydration. Bulging fontanels may indicate increased intracranial pressure or overhydration. Women have less bone mass than men, and lose bone mass at a faster rate and at an earlier age than men. Postmenopausal women have decreased blood concentrations of female sex hormones, resulting in further loss of bone mass and mineral content. The risk of developing osteoporosis may be reduced by increasing dietary calcium intake or taking a calcium supplement, regular exercise, abstaining from alcohol and smoking, and, in some postmenopausal women, hormone replacement therapy. A bone is lightweight because it has many spaces. An adult male and female, and a boy and a girl. Chapter 8 Ligaments are comprised of dense fibrous connective tissue, which has a poor blood supply. Cartilage is a rigid type of connective tissue that lacks a direct blood supply, resulting in slow cellular respiration and slow healing. The shoulder and hip joints are ball-and-socket joints in which the heads of the humerus and femur respectively fit into and are protected by bony sockets. These sockets, in turn, are surrounded by joint capsules, ligaments, and muscles that protect against injuries. The knee joint is of the condyloid and hinge types, has shallow articular surfaces, and is protected only by ligaments, thus making it more susceptible to injuries. The hip joint could be more satisfactorily replaced. The socket of the hip joint is deeper, its ligaments are larger and stronger, and it is surrounded by muscles. It also does not bear as much weight as the knee joint. There would be a loss of calcium, phosphorus, and matrix from the bones, resulting in bone destruction and brittleness. Keeping the joints mobile prevents stiffness, which leads to immobility. It also prevents contractures, or atrophy and shortening of muscles, which may result in permanent flexion of joints. Ligaments holding the articulating surfaces of the shoulder together are rather weak. Dislocating the shoulder would stretch or strain these ligaments, further weakening them, making future dislocations more likely. Chapter 9 Warm-ups improve athletic performance by increasing oxygen consumption during exercise (thus decreasing oxygen debt); flexibility of joints; capillary blood flow to muscles; and heart actions. The levator ani and coccygeus muscles. The caregiver performs active range-of-motion exercises of joints and muscles (that flex, extend, and rotate muscles and joints); periodically change the patient's position in bed. Heat application and its resulting vasodilation increase blood flow and oxygen to the site, promoting aerobic metabolism and the removal of lactic acid and other metabolic wastes. The gluteus medius muscle covers the superior lateral portion of the ilium. Bone markings that are used to establish the location of this muscle are the greater trochanter of the femur, the anterior superior iliac spine, posterior iliac spine, and crest of the ilium. Passively moving or electrically stimulating the injured muscle would help prevent muscle atrophy and contractures. Chapter 10 Tacrine might help sufferers of Alzheimer's disease. antagonist Axons of peripheral nerves are able to regenerate due to Schwann cells realigning themselves within the connective tissue endoneurium that forms a tube in which regenerating axonal sprouts are guided back to their original connections wwith the myoneural junction. Schwann cells also form new myelin around the growing axon. Motor nerve fibers within the spinal cord lack connective tissue sheaths, and the myelin-producing cells fail to produce new myelin following an injury. Low potassium ion concentration (hypokalemia) results in hyperpolarization (increased negativity) of nerve and muscle fiber membranes, which prevents transmission of nerve impulses. Administration of potassium ions causes these membranes to become less negative, reestablishing the resting membrane potential, thus restoring the nerve fibers' original excitability. Calcium. The developing fetus needs calcium from the pregnant woman for development of bones and teeth. This may result in a blood calcium deficiency in the woman, causing sodium channels to remain open and excessive diffusion of sodium ions through nerve fiber membranes, which leads to continuous impulse transmission to skeletal muscles, resulting in tetanic muscle spasms. Neuroglia are more numerous and can divide; mature neurons cannot divide. Multiple sclerosis strips myelin from neurons; Tay-Sachs disease wraps neurons in excess myelin. Chapter 11 The sample should be withdrawn from the subarachnoid space between L3 and L4, or L4 and L5. The patient should be positioned on his side with knees drawn up to the abdomen and his chin flexed down toward his chest (to increase spaces between the vertebrae). Right occipital lobe—loss of left half of visual field in each eye (left homonymous hemianopsis); Right temporal lobe—partial hearing loss in both ears, sensory aphasia if dominant hemisphere. Descending (motor) anterior, lateral, and corticospinal tracts in the spinal cord would be affected on the same side as the injury, causing paralysis. Ascending (sensory) lateral spinothalamic tracts for temperature and pain transmission crossover to the opposite side of the spinal cord before ascending, resulting in loss of these sensations below the level of the injury on that side of the body. If the biceps and triceps reflexes are present, the injury would be below C7. If the biceps and triceps reflexes are absent, the injury would be above C5. If the biceps reflex is present and the triceps reflex is absent, the injury would be between C5 and C7. Obstruction of tiny blood vessels of the cerebrum could cause a transient ischemic attack (temporary) or a stroke (permanent), resulting in weakness or paralysis of a limb, partial blindness, confusion, difficulty concentrating, memory loss, and decreased cognitive ability. The cause of the CVA will largely determine treatment. If it involved an obstructed blood vessel, carotid endarterectomies and anticoagulant therapy may be used in selected cases. If it involved a ruptured blood vessel, treatment may include antihypertensive and anticonvulsant medications; surgical removal of the hematoma or clipping of the vessel may be necessary if the bleeding was due to a ruptured aneurysm. Sweating, dilation of pupils, dry mouth, and increased pulse, blood pressure, and respiration. A person in a coma is not awake or aware. A person in a persistent vegetative state may experience periods of wakefulness. Chapter 12 The heat receptors in the skin have adapted to increased stimulation (by conducting fewer impulses to the brain). The bullet would probably be causing localized, rather than widespread, stimulation of pain receptors, due to acute (A-delta) fibers being stimulated. Crushing of the skin would stimulate more free nerve endings there and in subcutaneous tissues, resulting in stimulation of both acute and chronic pain fibers. Symptoms would include vertigo (dizziness), nausea, vomiting, headache, disequilibrium, tinnitus, and deafness. Since the cells of the retina would become separated from their supply of oxygen and nutrients, there would be progressive loss of vision and eventual blindness. Shorter, horizontally directed auditory tubes would enable microorganisms to enter the middle ear more easily, since the mucous membrane of the pharynx is continuous with that of the middle ear. Nerve impulses transmitting the sensation of pain from the heart follow common nerve pathways to the spinal cord and then to the brain as those originating from the skin of the left arm, shoulder, and the base of the neck. Chapter 13 The person would require more sugar. Stored glycogen could become depleted through glucagon stimulating the conversion of glycogen into glucose during exercise. Exercise, in turn, lowers blood glucose level by facilitating glucose transport into cells (essentially the same action as insulin) and by decreasing the rate of carbohydrate metabolism. Prolonged cortisol administration may result in: elevated blood glucose level (diabetes mellitus); edema; hypertension (due to retention of sodium); redistribution of body fat; muscle wasting (due to protein catabolism); osteoporosis (due to loss of calcium from bones); and decreased antibody response (which would impair wound healing and increase susceptibility to infections). Cool environment, well-balanced diet, quiet surroundings, relaxation, and simple diversional activities. Replacement hormones would include: glucocorticoids (cortisol); thyroxine; and sex hormones (estrogens, progesterone, testosterone; FSH, LH, and GH if a younger adult). If hypophysectomy was performed to slow metastatic breast cancer, sex hormones would not be administered. Why? Cortisol is necessary for life in order to regulate glucose, protein, and fat metabolism, and decrease inflammation. In adults, thyroxine is needed for regulation of the rate of glucose, protein, and fat metabolism. Sex hormones would maintain secondary sex characteristics and in a younger individual, might restore fertility. Aldosterone secretion would cause the blood concentration of sodium ions to increase and potassium ions to decrease. Growth hormone—Administration of GH would directly stimulate target cells to break down fats, and increase blood sugar levels and protein synthesis. GH would also directly stimulate bone tissue growth and mediate increased cartilage formation. Growth hormone-releasing hormone—Selection of GRH for administration would depend on the child's having a functioning anterior pituitary gland, which, in turn, would secrete GH. GH would then exert its stimulating effects on target cells and tissues. Chapter 14 The hematocrit would increase. Dehydration results from fluid loss exceeding fluid intake. This loss is replenished by the movement of water (and electrolytes) from plasma into the interstitial spaces and cells. Red blood cells are too large to pass through capillary walls, leaving a proportionately greater concentration of red blood cells in a lesser volume of plasma. EPO increases the oxygen carrying capacity of the blood, increasing athletic stamina. The white cell count would decrease. The patient's environment would need to be modified to decrease chances of infection (frequent hand washing, avoiding individuals with colds, administration of antibiotics if a fever is present, and avoiding raw foods). If hospitalized, additional precautions would include caregivers wearing a mask, a gown, and gloves, and giving the patient a private room. A deficient dietary intake of iron caused by lack of finances (foods high in iron, such as meats, seafood, and green leafy vegetables, may be expensive), physical limitations making it difficult to shop, lack of motivation to cook for oneself, and loss of teeth. The white blood cells formed in leukemia are immature and remain undifferentiated, and therefore have little or no ability to phagocytose bacteria or produce antibodies to combat infection. No. The Rh negative fetus would not have receptors for anti-Rh agglutinins on its red blood cell membranes. The blood of a person with hemophilia and HIV infection lacks clotting factor VIII and has deficient helper T cells, a type of lymphocyte. The liver manufactures clotting factors. Platelets do not contribute to blood type, as do the blood cells. Chapter 15 It would be wiser to rest. With exercise, blood flow to the myocardium, skin, and active muscles increases due to vasodilation (stimulated by sympathetic nerve stimulation, decreased partial pressure of oxygen, and decreasing pH). Conversely, sympathetic stimulation causes vasoconstriction and reduced blood flow to the digestive organs, which would impede digestion and absorption of nutrients if exercise were undertaken at this time, and could also result in cramping. Blood flow would probably carry the embolus to the pulmonary vessels. Symptoms would include dyspnea, chest pain, tachycardia, cough, spitting up blood (hemoptysis), and restlessness (due to cerebral hypoxia). The rate of venous return would decrease. Increased intrathoracic pressure compresses the walls of the large veins in the chest (superior and inferior venae cavae). The atria pump blood to the ventricles. During rest and moderate activity, filling of the ventricles is not dependent on atrial contraction. The ventricles pump arterial blood to the lungs and all body organs and tissues. During ventricular fibrillation, the ventricular myocardium quivers but does not contract as a whole, stopping cardiac output. Increased capillary pressure could cause varicosities in the thin-walled esophageal veins (known as esophageal varices), which may rupture, resulting in massive hemorrhage. It could also cause hemorrhoids, caput medusae (dilated cutaneous veins radiating out from the umbilicus), ascites, peripheral edema, and splenomegaly. Femoral artery, external iliac artery, common iliac artery, aorta (abdominal and thoracic), aortic arch, ascending aorta, and left coronary artery. An athlete might have an enlarged heart, and would have lower heart rate and blood pressure than a sedentary individual. Constriction of blood vessels elevates blood pressure. Carbon monoxide binding to hemoglobin impairs the oxygen-carrying capacity of the blood. An artificial heart must be able to contract, and must be constructed so that the direction of blood flow matches that of a natural heart. Chapter 16 Lymph nodes filter out, and thus trap, microorganisms and cancer cells as they travel between tissues and the bloodstream. Lymph node biopsy can, therefore, be used in diagnosing leukemias, cancers of the lymphatic system, metastatic cancers, and fungal infections (especially of the lungs). The dermis of the skin contains many lymph capillaries. Vaccination (vaccines) contains antigens that stimulate the body to produce antibodies for protection against a particular pathogen in the future. Thus, it provides active immunity. Gamma globulin contains antibodies not produced by the lymphocytes of the individual receiving the injection. Thus, no immunological memory is established as in the case of active immunity. Lymph nodes lie along lymphatic pathways. Thus, excising them interrupts the flow of lymph from tissues distal to the excisional site. The accumulation of tissue fluid and increased osmotic pressure in the fluid (due to the presence of plasma proteins, which lead out of lymph vessels) causes swelling. The infant's susceptibility to infections would increase. The thymus gland is the site of T-cell maturation. T-cell deficiency results in the individual having little or no resistance to intracellular virus, fungal, or bacterial infections. Choice b makes the most medical sense. a. First come, first serve is fair in that those who have been waiting the longest are the next to receive the organ. However, this system does not ensure the best matches between donors and recipients. Therefore it does not optimize survival. b. Giving priority to people with the closest tissue types matches would optimize the survival rate, but might not be fair to those waiting the longest. c. It could be argued that it is fairer to give a scarce medical resource to someone who did nothing to contribute to the disease. A smoker could be perceived as having knowingly engaged in a high risk behavior. However, nicotine addiction is in itself a medical condition. This strategy imposes a value judgment on the person seeking help. d. The argument for giving priority to the youngest is that they have the most years ahead of them. The youngest might not, however, have the most compatible tissue types with available organs. e. Some people believe in “Cadillac medicine,” that those with the most money should have the best treatment–like first class air travel. This idea is abhorrent to many people. f. Who is most important is highly subjective. Fetal tissue does not have as many antigens as tissue from an adult, and is therefore less likely to stimulate an immune response from a recipient. Exposure to antigens that commonly cause allergies during prenatal development might, theoretically, lessen the risk of developing those allergies. Exposing a fetus to certain antigens involved in tissue rejection might coax the body to be more receptive to transplanted tissue. Exposing children to other children helps to build their immune systems. A human body would normally reject a pig part nearly instantaneously, because it’s cell surfaces are unlike our own. A pig tissue with human antigens on it would be more likely to be accepted because the immune system (it is hoped) would recognize it as self. Chapter 17 Gastric secretions would be greatly reduced. Gastrin, which normally is the stimulus to secretory activity in the stomach, would be decreased; protein digestion, which normally begins in the stomach, would be decreased or absent due to the lack of pepsin and HCl; gastric lipase, which primarily digests butterfat, would be greatly decreased or not secreted at all. The patient would also be prone to pernicious anemia as a result of the removal of parietal cells of the stomach. Removal of 95% of the stomach would also reduce its storage capacity. The patient would need to eat several small meals per day and drink fluids between, rather than with, meals to avoid hypoglycemia and fluid loss through diarrhea. The cystic duct from the gallbladder empties into the common bile duct, which along with the main pancreatic duct empties into the duodenum at the hepatopancreatic sphincter. Cholecystitis (especially if accompanied by gallstones that block the common bile duct) often causes reflux of bile into the pancreatic duct, which activates pancreatic enzymes, leading to pancreatitis. In moderation, alcohol stimulates gastrin release, which would increase secretion of pepsin and HCl. This, in turn, would stimulate gastric peristalsis and pancreatic enzyme secretion, increasing digestive activity. Prolonged vomiting would result in alkalosis; prolonged diarrhea would result in acidosis. The starch blocker caused abdominal pain by blocking pancreatic amylase. Chapter 18 a. Weight loss depends upon the balance between calories in and calories out, not on the sequence in which foods are eaten. Some people may experience digestive distress from suddenly eating a very fatty food after several days of eating only fruit. b. The balance is nutritionally sound, but total number of calories is too low to be satisfying. c. The balance of this diet is sound, and it wisely includes exercise. However, the foods are unusual and may be difficult to obtain. d. Nucleic acids in foods are digested as are other nutrients. There is no scientific evidence that ingesting them extends life. The recommended foods eaten in excess may add too much fat to the diet. Blood sugar (glucose) concentration would remain stable due to glycogenolysis, which converts glycogen into glucose, and gluconeogenesis, in which certain amino acids can be deaminated and converted into glucose. Vitamins do not directly provide energy, as carbohydrates do. They do, however, enable the enzymes that extract energy from nutrients to function. In this way, vitamins indirectly boost energy. This high-fat meal is difficult and slow to digest. A meal rich in carbohydrates is a more sensible pregame meal. The reasons for anorexia nervosa are rooted in a sufferer's distorted perception of her weight. Without protein, the immune system's ability to fight off infection is severely compromised. To calculate caloric content of nutrients, multiply grams of carbohydrate by 4.1 (Cal./gm), grams of lipid by 9.5 (Cal./gm), and grams of protein by 4.1 (Cal./gm). According to National Research Council figures, carbohydrates should comprise 50% of daily caloric intake, proteins 15–20%, and fats 30–35%. Daily energy needs (Calories) per day are: Age Males Females 15–18 2,800 2,100 19–22 2,900 2,100 23–50 2,700 2,000 Answers will vary. Fish (contains all the essential amino acids) and proteins of plant origin (contain selected amino acids, when eaten in variety provide all essential amino acids) such as rice, beans, peas, nuts, and seeds. Avoid eating egg yolks, liver and other organ meats; eat meat, cheese, butter, and whole milk in moderation; select a diet high in fruits, vegetables, bread, and cereals. The twelve-year-old boy would require more calories, protein, carbohydrates, fats, and B vitamins than the man. A pregnant woman requires more calories than the boy or the man. Chapter 19 Air entering a tracheostomy would not be warmed, filtered for removal of microorganisms and dust particles, or humidified by the nasal passages or oropharynx. The patient may experience irritation around and inside the tracheostomy opening (due to dryness), coughing, and respiratory infections. Residual volume would increase due to overdistension of the lungs and loss of elastic recoil force from destruction of alveolar walls. This would increase pressure in the pleural cavity and inhibit expiration of air from the lungs. Expiratory reserve volume would be decreased due to loss of elastic recoil force of the alveoli. Vital capacity would decrease due to residual volume taking up more of the thoracic gas volume (total lung capacity). Total lung capacity would remain the same or would increase due to overdistension of the lungs, increased anterior-posterior diameter of the chest wall, and increased residual volume. Concentration of blood oxygen would increase due to deep and rapid inhaling of air, which is 21% oxygen. The mixture of oxygen and carbon dioxide would be more beneficial. Carbon dioxide would normally stimulate the respiratory center and oxygen would prevent tissue hypoxia. At high altitudes, the partial pressure of oxygen is less, which would stimulate chemoreceptors in the carotid and aortic bodies, resulting in an increased respiratory rate. If the individual is unable to breathe at this increased rate, oxygen will diffuse less rapidly from the alveoli into the blood and the tissues, including the brain, and the person will become hypoxic and lose consciousness. Pursed lip breathing slows the flow rate of exhaled air. This creates a back pressure in the airways, which keeps the smaller airways open, preventing their collapse and obstruction. Thus, the lungs will ‘‘empty’’ more completely. Chapter 20 The volume of urine would decrease. Narrowed renal arteries would decrease blood flow to the glomeruli, which, in turn, would decrease glomerular filtration rate, glomerular filtrate, and urine. Plasma proteins include the gamma globulin fraction, which includes immunoglobulins. Immunoglobulins produce antibodies that defend against infection. The volume of urine produced would probably be greater than normal. Loss of blood would mean loss of plasma proteins, which, in turn, would decrease plasma osmotic pressure. Intravenous fluids would maintain blood volume and blood pressure, but would contain no plasma proteins to oppose hydrostatic pressure, which promotes production of glomerular filtrate and urine. Since penicillin is excreted unchanged and concentrated in the urine, the penicillin will act while the urine is in the urinary bladder. Therefore, the route to the bladder is through the kidneys. Absorption into capillaries of the small intestine, venules, superior mesenteric vein, portal vein, liver, hepatic vein, inferior vena cava, heart, aorta, renal arteries, kidneys (glomeruli, glomerular capsule, tubules, collecting ducts, renal pelvis), ureters, urinary bladder. The volume of urine would decrease. (Shock results in sympathetic vasoconstriction of peripheral vessels and decreased glomerular filtration rate. In response to decreased glomerular filtration rate, the renin-angiotensin mechanism is activated, which increases circulating blood volume.) The female urethra is shorter (4 cm long vs. 19 cm in the male) than that of the male. Therefore, microorganisms could ascend into the bladder more readily. Chapter 21 Partial pressure of carbon dioxide would increase and partial pressure of oxygen would decrease. Oxygen saturation of red blood cells would also decrease. Symptoms would include: dry, sticky mucous membranes; lethargy (with irritability when disturbed); tremors; convulsions; muscle rigidity; and edema. Infants have proportionately more extracellular than intracellular water (hence, they have less reserve to draw on to ‘‘dilute’’ the sodium), their kidneys are immature and less able to conserve water, and they have greater body surface area in proportion to weight, resulting in increased fluid loss through perspiration. Concentrated protein feedings through a gastrostomy tube would pull water osmotically into the intestine from the blood and extracellular fluid, causing diarrhea, dehydration, and increased serum sodium level. Plasma pH would: a. decrease b. increase c. increase d. decrease Absorption would be impaired, therefore the patient would be prone to hyponatremia and hypokalemia. Fluid would accumulate in the extracellular fluid compartments, resulting in edema, ascites, and increased venous pressure. Chapter 22 There would be no significant decrease in secondary sex characteristics following removal of one testis. Removal of both testes would result in decreased rate of growth of the beard and body hair due to significant reduction in testosterone production. Removal of the prostate gland would have no effect on secondary sex characteristics. No. Menstruation is dependent on hormone secretion (by the anterior pituitary gland and ovaries). Tubal ligation has no effect on hormone secretion. If a single ovary is removed, there is no change in the menstrual cycles; if both ovaries are removed, the menstrual cycles would cease, due to significant reduction in production of estrogen and progesterone. The consequences would be infertility. The higher temperature in the abdominal cavity inhibits sperm formation. The most effective methods of contraception are tubal ligation, vasectomy, contraceptive implant, and oral contraceptives. The least effective methods of contraception are coitus interruptus, rhythm method, diaphragms, and jellies. If an entire sperm cell was injected into an egg cell, its cell membrane might prevent the sperm cell's nucleus from merging with that of the egg cell. a. Combined hormone contraceptives b. Intrauterine devices c. Tubal ligation d. Vasectomy Polar body is small. When the primary oocyte divides, the distribution of the cytoplasm is unequal. One of the resulting cells, called a Secondary oocyte, is large, and the other, called first oocyte represents a future egg cell (ovum) that can be fertilized by uniting with a sperm cell. Chapter 23 Identical twins are genetically identical. Therefore, they have identical antigens that would not stimulate cell-mediated and antibody-mediated immune responses. Problems could include mixing of oxygenated and deoxygenated blood in the right and left ventricles, resulting in cyanosis and hypoxia of body organs. It could also result in increased distension and workload of the right ventricle, which would impede circulation of blood to the lungs and result in already-oxygenated blood being recirculated through the lungs. Symptoms could include those of congestive heart failure (cyanosis, fatigue, and peripheral and pulmonary edema). A fetus grown in a laboratory (not possible) would have to be kept warm, given nutrients and oxygen, and its wastes removed. The physically inactive adult's skeletal muscles will have begun to lose strength; joint mobility and bone density would be decreased; vital capacity would be decreased; and narrowing of arterial lumens could lead to hypertension and less efficient pumping of blood from the heart. Environmental provisions could include: reducing background noise; marking stairways clearly; providing night lights and higher wattage reading lamps; avoiding use of scatter rugs; applying nonslip strips in bathtubs; avoiding electric heaters; providing firm chairs; serving a low-sugar, low-salt, low-fat, high-fiber, high-calcium diet; encouraging fluid (water) intake and clearly labeling medication containers. Chapter 24 DNA microarray tests performed early in life can provide information that individuals can use to alter their lifestyles, such as adopting healthful dietary and exercise habits. A major disadvantage is that such a test cannot account for the environmental component of a trait. Some people might take a fatalistic approach, “since it’s in my genes, I shouldn’t try to change things.” An autosomal recessive trait or illness can appear to come from nowhere in a family because it is carried in heterozygotes, who transmit the diseasecausing allele but are not themselves affected by the illness. The phenotype is altered, and not the genotype, because the change does not occur to his sperm cells. The probability that the fourth child inherits sickle cell disease is 1 in 4—the same as for any other child of these parents. Each conception is an independent event. A DNA microarray test to detect individuals prone to lung cancer and addictive behaviors could be beneficial in warning certain people away from smoking. It might be dangerous, though, by giving those without an increased risk of developing lung cancer a false sense of security—they could still be at risk for developing emphysema, hypertension, heart disease, or other conditions associated with smoking. a. 1/2 b. 1/2 c. 1/2 The female is less severely affected because she has a functional copy of the gene on her second X chromosome. The male does not. Medium brown skin colors are more common than very black or very white because there are more allele combinations that result in this color, because this is a polygenic trait. There are fewer Y-linked traits than there are Y-linked genes because some of the genes on the Y chromosome have counterparts on the X chromosome. “Any aneuploid” refers to the fetus having any of the chromosomes missing or extra. A person successfully treated for the symptoms of CF can indeed pass the disease-causing allele to offspring, because the gene is not changed in the sperm or egg. Difficulties in treating Parkinson disease with gene therapy include getting the therapeutic gene into the brain, targeting the correct brain cells, and achieving a sustained effect. If gene therapies need to be rationed for disorders that can be caused by genes directly, or by risky behaviors, some people might argue that the genetic cases be given priority because the disease is out of the person’s control. Others might argue that the addictive behavior is not under the person’s control. Another criterion for determining who receives a scarce medical resource is to consider which individuals are the most likely to benefit from the treatment.