Correct Answer: B

Rationale: Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. The number of dissolved particles contained in a unit of fluid determines the osmolality of a solution, which influences the movement of fluid between the fluid compartments. Giving a patient who has a low blood pressure a hypertonic solution will increase the number of dissolved particles in the blood, creating pressure for fluids in the tissues to shift into the capillaries and increase the blood volume. Option A is incorrect; hydrostatic pressure refers to changes in water or volume related to water pressure. Option C is incorrect; diffusion is the movement of solutes from an area of greater concentration to lesser concentration. The solutes in an intact vascular system are unable to move, so diffusion should not normally take place. Option D is incorrect; active transport is the movement of molecules against the concentration gradient and requires ATP as an energy source. This process typically takes place at the cellular level and is not involved in vascular volume changes.

Correct Answer: A

Rationale: Increased serum sodium causes increased thirst and the release of ADH by the posterior pituitary gland.

Correct Answer: D

Rationale: Bananas are high in potassium. Apples, carrots, and asparagus are not high in potassium.

Correct Answer: B

Rationale: The most common cause of acute respiratory alkalosis is hyperventilation. Extreme anxiety can lead to hyperventilation.

Correct Answer: C

Rationale: The kidneys regulate the bicarbonate level in the ECF; they can regenerate bicarbonate ions as well as reabsorb them from the renal tubular cells. In respiratory acidosis and most cases of metabolic acidosis, the kidneys excrete hydrogen ions and conserve bicarbonate ions to help restore balance.