ATI Fluid and Electrolytes

Correct Answer: B

Rationale: The correct answer is 'aldosterone.' Aldosterone is the hormone that reduces the amount of water in the body by increasing the reabsorption of sodium and water from the kidney tubules. ANH (atrial natriuretic hormone) actually works to increase the excretion of sodium and water by the kidneys, leading to a reduction in blood volume and pressure. ADH (antidiuretic hormone) works to increase water reabsorption by the kidneys, thereby increasing blood volume. Therefore, choices A (ADH) and D (ADH and aldosterone) are incorrect in the context of reducing the amount of water in the body.

Correct Answer: A

Rationale: The correct answer is A: Kidneys. The kidneys play a crucial role in regulating the amount of sodium in the body. They achieve this by filtering blood and controlling the excretion or reabsorption of sodium. The small intestine is primarily responsible for nutrient absorption, not sodium regulation. The large intestine is mainly involved in water absorption and waste elimination, not sodium balance. The skin helps regulate body temperature through sweating and does not directly regulate sodium levels.

Correct Answer: C

Rationale: Inelastic skin is a normal change of aging. However, this does not mean that skin turgor cannot be assessed in older patients. Dehydration, not overhydration, causes inelastic skin with tenting. Overhydration, not dehydration, causes the skin to appear edematous and spongy. Choice A is incorrect because overhydration is not common among healthy older adults. Choice B is incorrect because dehydration leads to inelastic skin, not sponginess. Choice D is incorrect as skin turgor assessment can be done in patients of any age, including those over 70.

Correct Answer: C

Rationale: The correct answer is C: 'adjust fluid output so it equals fluid input.' Maintaining fluid balance involves ensuring that the amount of fluid lost through processes like urination, sweating, and respiration equals the amount of fluid taken in. This ensures that the body stays properly hydrated. Choices A, B, and D are incorrect because they do not focus on the balance between fluid input and output, which is crucial for maintaining proper fluid balance. By adjusting fluid output to equal fluid input, the body can regulate hydration levels effectively, preventing dehydration or overhydration.

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.