What is the main water-holding force in the blood capillaries?

Correct Answer: C

Rationale: The correct answer is C: Protein in the blood plasma. Plasma proteins, especially albumin, create oncotic pressure, which is the main force responsible for holding water within the blood capillaries. Capillary blood pressure (Choice A) is involved in pushing blood through the capillaries, while sodium and chloride in the blood plasma (Choices B and D) are electrolytes and do not play a significant role in the water-holding force within capillaries.

Correct Answer: C

Rationale: In dehydration, the body first draws fluid from the interstitial space to maintain blood volume, leading to a decrease in interstitial fluid volume. This is why choice C is correct. Choice A is incorrect because intracellular fluid is not the first to be affected. Choice B is also incorrect as plasma volume reduction typically occurs after interstitial fluid loss. Choice D is incorrect as dehydration impacts both interstitial and intracellular fluid volumes.

Correct Answer: D

Rationale: Dehydration can result from significant fluid loss due to vomiting, diarrhea, or inadequate fluid intake. Prolonged vomiting and diarrhea lead to excessive fluid loss from the body, contributing to dehydration. Similarly, not consuming enough fluids can also result in dehydration. Choice A and B are too specific as they only mention one cause each, while choice C is also correct but does not encompass all the potential causes of dehydration as mentioned in choice D.

Correct Answer: C

Rationale: The correct answer is C. Overhydration can occur when intravenous fluids are administered too quickly, overwhelming the body's ability to excrete the excess fluid. Choices A, B, and D are incorrect. Choice A is incorrect because overhydration is less common than dehydration. Choice B is incorrect because while overhydration can strain the kidneys, it is not due to the burden being too heavy. Choice D is incorrect because dehydration is more common than overhydration.

Correct Answer: D

Rationale: The correct answer is D. Cerebrospinal fluid and the humors of the eye are not considered extracellular fluids. Extracellular fluids are fluids found outside the cells, such as interstitial fluid and lymph. Cerebrospinal fluid is found within the central nervous system, while the humors of the eye (aqueous humor and vitreous humor) are located within the eyeball, making them distinct from extracellular fluids.