Which of the following is not considered a function of the kidneys?

The kidneys play a crucial role in maintaining homeostasis in the body through several key functions, including secretion, reabsorption, and filtration.

Secretion refers to the process by which the kidneys remove certain substances from the blood, adding them to the urine, which helps regulate the levels of various electrolytes and metabolic waste. This function is essential for eliminating toxins and maintaining the body's chemical balance.

Reabsorption is the mechanism by which substances that the body needs, such as water, glucose, and certain ions, are reabsorbed from the filtrate in the renal tubules back into the blood. This process ensures that vital nutrients and adequate water levels are conserved, preventing excessive loss in urine.

Filtration is the initial step in urine formation where blood enters the kidneys, and through the glomeruli—special structures within the kidneys—fluid and small solutes are filtered out of the blood to form a precursor to urine called filtrate. This process is fundamental for waste removal and fluid balance.

Transport, while it may occur in the context of urine moving through the urinary tract after formation, is not a primary function attributed directly to the kidneys themselves in terms of metabolic processing. The primary functions of the kidneys focus on filtering blood, reabsorbing