An efferent arteriole is a blood vessel that transports blood away from the glomerulus. The blood is carried either to the vasa recta or to the peritubular capillaries.
The efferent arteriole is an important component in the human urinary tract system. It is found alongside the afferent arteriole in the glomerulus, which refers to a cluster of capillaries in the kidneys. The efferent arteriole functions by emptying the glomerulus of its filtered blood content through a pressure gradient mechanism.
In the exterior of the glomerular renal cortex, the efferent arterioles form the peritubular network of capillaries that encloses the kidney tubules. These tiny blood vessels reabsorb the water, ions and nutritive particles from the blood. The plasma that enters the renal medulla travels through the vasa recta, which is formed from the efferent arterioles in the innermost portion of the glomerular renal cortex.