ATI Fluid and Electrolytes

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: D

Rationale: Assessing the specific gravity in a patient with SIADH helps the nurse evaluate the patient's fluid volume status. Specific gravity indicates the concentration of solutes in the urine and can detect if the patient has a fluid volume deficit or excess. Nutritional status, potassium balance, and calcium balance are not directly assessed through specific gravity testing. Nutritional status is typically evaluated through dietary intake and anthropometric measurements. Potassium balance is assessed through blood tests and ECG monitoring. Calcium balance is evaluated through blood tests and bone density scans. Therefore, the correct answer is assessing fluid volume status through specific gravity testing.

Correct Answer: B

Rationale: The correct answer is B: Osmosis and osmolality. Osmosis is the movement of fluid from a region of low solute concentration to a region of high solute concentration across a semipermeable membrane. In this case, the hypertonic solution increases the number of dissolved particles in the blood, causing fluids to shift into the capillaries due to the osmotic pressure gradient. Osmolality refers to the concentration of solutes in a solution. Hydrostatic pressure refers to changes in water or volume related to water pressure, not the movement of fluids due to solute concentration differences. Diffusion is the movement of solutes from an area of greater concentration to lesser concentration; in an intact vascular system, solutes are unable to move freely, so diffusion does not play a significant role in this scenario. Active transport involves the movement of molecules against the concentration gradient with the use of energy, typically at the cellular level, and is not related to the vascular volume changes described in the question.

Correct Answer: C

Rationale: Aldosterone increases the reabsorption of sodium in the kidneys, which leads to an increase in blood volume and blood pressure. Choice A is incorrect as aldosterone does not regulate body temperature. Choice B is incorrect as aldosterone increases blood pressure by increasing sodium reabsorption. Choice D is incorrect as aldosterone promotes water retention by increasing sodium reabsorption.

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.