AEMCA Practice Exam

What role do peritubular capillaries play in kidney function?

1. Filtration of blood

2. Reabsorption of minerals and nutrients

3. Secretion of waste

4. Regulation of blood pressure

The correct answer is: Reabsorption of minerals and nutrients

Peritubular capillaries play a crucial role in the kidney's function by facilitating the reabsorption of minerals and nutrients from the tubular system back into the bloodstream. After the initial filtration of blood occurs in the renal corpuscle, various substances such as water, electrolytes, glucose, and amino acids are filtered into the nephron. These substances can be reabsorbed across the walls of the nephron tubules. The peritubular capillaries surround the nephron tubules and allow for the efficient exchange of these reabsorbed substances. As the filtrate passes through the proximal convoluted tubule and other segments of the nephron, important nutrients and minerals are actively or passively transported back into the peritubular capillaries. This process is essential for maintaining homeostasis and ensuring that essential nutrients are not lost in urine. This function is particularly important in controlling the body's overall electrolyte balance, hydration status, and nutrient levels in the bloodstream. Therefore, the primary role of peritubular capillaries in kidney function is indeed related to the reabsorption of minerals and nutrients.