Peritubular capillary

Peritubular capillaries are tiny blood vessels, located in the kidney, that function in the reabsorption of substances into the blood from the renal tubules. They are part of the renal circulation system and play a crucial role in the process of urine formation.

Structure

Peritubular capillaries are located around the renal tubules, hence the name 'peritubular'. They originate from the efferent arteriole, which is the blood vessel that exits the glomerulus. The capillaries form a network around the renal tubules, particularly the proximal tubule and the distal tubule.

Function

The primary function of the peritubular capillaries is to reabsorb useful substances such as water, glucose, and amino acids that have been filtered out of the blood in the glomerulus and passed into the renal tubules. This reabsorption process is essential for the body to retain necessary substances that would otherwise be lost in the urine.

The peritubular capillaries also collect waste products that have been secreted into the renal tubules from the blood. These waste products include urea, creatinine, and certain drugs and toxins. The waste products are then carried away in the blood and eventually excreted in the urine.

Clinical significance

Damage to the peritubular capillaries can lead to various kidney diseases. For example, in acute tubular necrosis, the peritubular capillaries can become blocked, leading to a decrease in reabsorption and an increase in waste products in the blood. In chronic kidney disease, the peritubular capillaries can become scarred, leading to a decrease in their function and eventually to kidney failure.

See also

• Renal physiology
• Nephron
• Renal corpuscle
• Renal tubule