anim_water_fluid_flow_answer_key.doc

Water and Fluid Flow To complete this worksheet, select: Module: Balancing Fluids Activity: Animations Title: Water and Fluid Flow Introduction 1. Regulation of body fluid composition is critical to homeostatic maintenance. As you’ve seen, body fluids are primarily water, however, there are other molecules dissolved into it. Identify those molecules. Dissolved solutes, nutrients, gases such as oxygen and carbon dioxide, nitrogenous waste, electrolytes, and proteins. Roles of Water 2. Identify basic roles of water in the body. Water is used for transportation, participation in reactions, lubrication and temperature regulation. 3. Explain some details about water’s transportation role. It is the primary medium for the transportation of all substances in both blood and lymph. 4. Describe water’s role in each of the following types of chemical reactions. Dehydration Synthesis – Water is needed in chemical reactions. In order to make larger molecules from smaller ones, water must be removed. Hydrolysis – In order to make smaller molecules from larger ones, water must be added to the chemical reaction. 5. Water is the chemical environment for all body reactions. Explain. All reactions in the body occur within aqueous solutions. Without water the cells would not be able to build new molecules or get energy from fuel molecules. 6. Describe how water functions to regulate temperature. Water can absorb and release large amounts of heat. Sweating removes excess heat with water vapor. Body temperatures above normal are not conducive to maintaining homeostasis. 7. Describe the lubrication role of water and serous membranes. Water makes up most of the lubricating fluid between organs. Serous and mucous membranes use watery substances to reduce friction and allow movement between organs that are in contact with each other. Movement of Fluids 8. Explain the correlation between solute concentrations, osmotic pressure, and water movement. In order for water to carry out its functions it must be moved form one compartment into another.. To move water, cells must move solutes first. Increase solutes cause an increase in osmotic pressure and relatively low amounts of water. Water flows by diffusion towards fluids with high osmotic pressures.. The diffusion of water is called osmosis. Important Uses of Fluid Flow 9. Fluid movement is important to its function in many body locations. a. How is fluid movement critical for capillary function? Water and dissolved solutes are exchanged between the blood and the body’s cells in the capillaries. b. How is fluid movement critical for nephron function? The nephron reclaims water and solute from the urine and returns these substances to the blood. As it returns them the blood volume and composition are altered. c. How is water critical for digestion and absorption? Mucus, which consists mainly of water, is used in the digestive system via hydrolysis reactions to lubricate the movement of food and aid in digestion. Water, along with other nutrients, is absorbed back into the mucosa. Water is also a necessary component for the hydrolysis of nutrients. d. How is water critical for respiration? The water in mucus, produced by the respiratory mucosa, has a role in cleaning air prior to gas exchange in the lungs. It also plays a role in the humidification of air as it enters the respiratory passageways. Additionally, the moist surfaces of the alveoi promotes the exchange of gases between the air the blood.