Question 23

Aldosterone conserves sodium in the body.

Aldosterone's primary function is to regulate sodium levels in the body, thereby playing a crucial role in maintaining blood pressure and fluid balance.

A) It converts proinsulin to insulin.

This option is incorrect because the conversion of proinsulin to insulin is primarily the function of enzymes in the pancreas, not aldosterone. Aldosterone does not have any direct role in insulin synthesis or regulation.

B) It conserves sodium in the body.

This option is correct as aldosterone acts on the kidneys to promote the reabsorption of sodium ions from the urine back into the bloodstream, which helps to maintain blood volume and pressure.

C) It protects against stress.

This option is incorrect because while aldosterone is involved in the body's response to stress, its primary function is not to protect against stress but to regulate electrolyte balance. The stress response is more closely associated with hormones like cortisol.

D) It affects heat production.

This option is incorrect as aldosterone does not play a role in heat production. Heat production in the body is primarily regulated by metabolism and thyroid hormones, not by aldosterone.

Conclusion

Aldosterone is definitively identified as the hormone responsible for conserving sodium in the body, which is vital for regulating blood pressure and overall fluid balance. The other options either misattribute functions to aldosterone or relate to different physiological processes that do not involve this hormone, thereby confirming that B is the only correct choice.