Interstitial fluid makes up what percentage of intracellular fluid?

Correct Answer: A

Rationale: The correct answer is A (0 percent) because interstitial fluid is the fluid that surrounds the cells outside of the cell membrane, not the fluid within the cells themselves. Intracellular fluid refers to the fluid inside the cells, which does not include interstitial fluid. Therefore, interstitial fluid does not make up any percentage of intracellular fluid. Explanation for other choices: B: 25 percent - This is incorrect because interstitial fluid is not part of intracellular fluid, so it cannot make up a percentage of it. C: 50 percent - This is incorrect as well for the same reason as above. D: 75 percent - This is also incorrect because interstitial fluid is not part of intracellular fluid at all.

Correct Answer: B

Rationale: The correct answer is B: plasma proteins. Plasma proteins contribute the vast majority of extracellular fluid's osmotic activity due to their high concentration and large size, which results in significant osmotic pressure. This osmotic pressure helps maintain fluid balance and regulate the movement of water between compartments. Na+ and its attendant anions (Choice A) are important for fluid balance but do not contribute significantly to osmotic activity. K+ and its attendant anions (Choice C) are mainly intracellular ions and do not play a major role in extracellular osmotic activity. Ca2+ and its attendant anions (Choice D) are essential for various cellular functions but do not contribute significantly to extracellular osmotic activity.

Correct Answer: B

Rationale: Correct Answer: B - Decreased K+ in the ECF Rationale: 1. Renin is released by the kidneys in response to decreased arterial blood pressure (A), decreased plasma volume (C), and decreased Na+ in the ECF (D). 2. Aldosterone release is stimulated by decreased plasma volume and decreased Na+ in the ECF, but not by decreased K+ in the ECF. 3. The renin-angiotensin-aldosterone system is primarily involved in regulating Na+ and water balance, not K+ levels. Summary: A, C, and D are incorrect because they can trigger the renin-angiotensin-aldosterone system. Choice B is the correct answer as decreased K+ levels do not directly activate this system.

Correct Answer: A

Rationale: Step 1: Increased ECF osmolarity causes osmoreceptors to detect the change. Step 2: Osmoreceptors signal the hypothalamus to release ADH (vasopressin). Step 3: ADH increases water reabsorption in the kidneys. Step 4: Water shifts from the ICF into the ECF to restore osmotic balance. Therefore, choice A is correct. Choices B and C are incorrect because changes in osmolarity trigger water movement. Choice D is incorrect because vasopressin secretion would actually increase to help restore water balance.

Correct Answer: B

Rationale: The correct answer is B: disorientation and coma. Acidosis occurs when the body's pH level becomes too acidic. This leads to central nervous system dysfunction, resulting in disorientation and potentially coma. Extreme nervousness (A) is not a typical symptom of acidosis. "Pins and needles" sensations (C) are more commonly associated with nerve damage or circulation issues. Muscle twitches and spasms (D) are not specific to acidosis and can occur due to various reasons. In summary, disorientation and coma are key indicators of acidosis due to the impact on the central nervous system.