Dunphy Endocrine and Metabolic Problems Practice Test

Aldosterone is a steroid hormone produced by the adrenal cortex, and it plays a crucial role in regulating electrolyte balance and blood pressure. Its primary physiological effects include promoting sodium reabsorption in the kidneys, which leads to increased sodium retention. As sodium is reabsorbed back into the bloodstream, water follows osmotically; thus, aldosterone also contributes to water retention, which can increase blood volume and blood pressure.

Additionally, aldosterone enhances the excretion of potassium by acting on the distal convoluted tubule and collecting duct of the nephrons. This action helps maintain proper potassium levels in the body, as excessive potassium can lead to serious health issues.

The option indicating that aldosterone increases sodium retention, potassium excretion, and consequently water retention accurately describes its physiological functions, making it the correct choice. This comprehensive activity of aldosterone is vital for maintaining homeostatic balance in the body, particularly regarding fluid volume and electrolyte concentrations.