Anatomy and Physiology II Practice Test

Aldosterone is a steroid hormone produced by the adrenal cortex and plays a crucial role in regulating blood pressure and fluid balance in the body. Its primary function involves promoting the reabsorption of sodium (Na+) in the kidneys. When sodium is reabsorbed, water tends to follow osmotically, leading to an increase in the volume of extracellular fluid.

By increasing sodium levels in the extracellular fluid, aldosterone effectively expands this compartment. This increase in extracellular fluid can also lead to a rise in blood volume and, consequently, blood pressure, which is essential for maintaining adequate perfusion to organs. Thus, the impact of aldosterone is to enhance the amount of extracellular fluid in the body.

This understanding of aldosterone’s function is crucial in the context of fluid balance and overall homeostasis, linking hormonal regulation to changes in fluid compartments within the body.