Answers to work sheet
Fluid, Electrolyte, and pH Balance
Utilizing knowledge from your learning and assigned readings, respond to the following questions:
1. The maintenance of normal volume and composition of extracellular and intracellular fluids is vital to life. List and briefly describe the kinds of homeostasis involved.
2. Why does maintaining fluid balance in older people require a higher water intake than in a normal, healthy adult under age 40?
3. Why does potassium concentration rise in patients with acidosis? What is this called? What effects does it have?
4. Saline solution is used to reverse hypotonic hydration. Are body cell membranes permeable to saline? Explain your response.
5. Explain the renin-angiotensin mechanism.
6. Explain how ADH compensates for blood that contains too many solutes.
Answers
1. Three types of homeostasis are involved: fluid balance, electrolyte balance, and acid-base balance. Fluid balance means that the total quantity of body water remains almost constant and that the distribution between the ICF and ECF are normal. Electrolyte balance implies the same thing for ions. Acid-base balance means that the pH of the ECF is maintained in the range of 7.35 to 7.45, and that gains or losses of hydrogen ion as a consequence of metabolism are followed by equivalent losses or gains so as to maintain constant buffer reserves.
2. Maintaining adequate fluid balance is an essential component of health across the life span; older adults are more vulnerable to shifts in water balance, both over hydration and dehydration, because of age-related changes and increased likelihood that an older individual has several medical conditions. Dehydration is the more frequently occurring problem.
3. When pH is low, hydrogen ion levels in the blood are high and also in the interstitial and peritubular fluid. Hydrogen ion competes with potassium ion for the sodium countercurrent exchanger in the tubules. As hydrogen ion secretion rises (which compensates for the
Utilizing knowledge from your learning and assigned readings, respond to the following questions:
1. The maintenance of normal volume and composition of extracellular and intracellular fluids is vital to life. List and briefly describe the kinds of homeostasis involved.
2. Why does maintaining fluid balance in older people require a higher water intake than in a normal, healthy adult under age 40?
3. Why does potassium concentration rise in patients with acidosis? What is this called? What effects does it have?
4. Saline solution is used to reverse hypotonic hydration. Are body cell membranes permeable to saline? Explain your response.
5. Explain the renin-angiotensin mechanism.
6. Explain how ADH compensates for blood that contains too many solutes.
Answers
1. Three types of homeostasis are involved: fluid balance, electrolyte balance, and acid-base balance. Fluid balance means that the total quantity of body water remains almost constant and that the distribution between the ICF and ECF are normal. Electrolyte balance implies the same thing for ions. Acid-base balance means that the pH of the ECF is maintained in the range of 7.35 to 7.45, and that gains or losses of hydrogen ion as a consequence of metabolism are followed by equivalent losses or gains so as to maintain constant buffer reserves.
2. Maintaining adequate fluid balance is an essential component of health across the life span; older adults are more vulnerable to shifts in water balance, both over hydration and dehydration, because of age-related changes and increased likelihood that an older individual has several medical conditions. Dehydration is the more frequently occurring problem.
3. When pH is low, hydrogen ion levels in the blood are high and also in the interstitial and peritubular fluid. Hydrogen ion competes with potassium ion for the sodium countercurrent exchanger in the tubules. As hydrogen ion secretion rises (which compensates for the