ATI Fluid and Electrolytes

Correct Answer: B

Rationale: Iodine is the correct answer because it is essential for the synthesis of thyroid hormones. The thyroid gland incorporates iodine into thyroid hormones such as thyroxine (T4) and triiodothyronine (T3). These hormones are crucial for regulating metabolism, growth, and development. Sodium, iron, and chloride are not directly involved in the formation of thyroid hormones, making them incorrect choices.

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, blood pressure. Blood pressure is the primary force that pushes fluid out of the capillaries into the surrounding tissues. This pressure difference is essential for the exchange of nutrients, gases, and waste products between the blood and tissues. Choices B, C, and D are incorrect as they do not represent the primary force responsible for pushing fluid in blood capillaries.

Correct Answer: C

Rationale: Dehydration leads to a decrease in the body's fluid levels, causing the salivary glands to produce less saliva, resulting in a dry mouth. Therefore, when dehydration begins to occur, salivary secretions decrease. Choice A is incorrect because the body does not reduce fluid output to zero during dehydration; it tries to conserve fluids. Choice B is incorrect as dehydration does not directly increase the release of ANH (Atrial Natriuretic Hormone). Choice D is incorrect because salivary secretions do not increase but decrease during dehydration.

Correct Answer: D

Rationale: The correct answer is D, ADH and aldosterone. Both antidiuretic hormone (ADH) and aldosterone increase water retention by the kidneys, thereby increasing blood volume. ADH acts on the kidneys to increase water reabsorption, while aldosterone acts on the kidneys to promote sodium reabsorption, leading to water retention. Choice A, ADH, is partially correct as it alone increases water retention. Choice B, aldosterone, is also partially correct as it alone increases water retention. Choice C, ANH (atrial natriuretic hormone), actually decreases water retention by promoting sodium excretion and inhibiting aldosterone release.