What is the primary function of mineralocorticoids, such as aldosterone?

Mineralocorticoids, particularly aldosterone, play a crucial role in maintaining electrolyte balance and fluid homeostasis in the body. Their primary function is to promote the retention of sodium by the kidneys. When aldosterone is secreted, it acts on the cells of the distal tubules and collecting ducts in the nephron, increasing the reabsorption of sodium from the urine back into the bloodstream. This sodium retention leads to the retention of water, which helps to maintain blood pressure and blood volume.

In addition to sodium reabsorption, aldosterone also promotes the excretion of potassium, contributing to overall electrolyte balance. This action is vital for regulating blood pressure and ensuring adequate blood flow to tissues. Thus, understanding the role of mineralocorticoids highlights their importance in the endocrine system and how they maintain homeostasis.