Where are the efferent arterioles located?

The efferent arterioles are found in the renal system, which contains the kidneys, and is part of the urinary system. The role of the kidneys is to filter blood and extract urine and waste. From the kidneys, the urine goes to the bladder where it is ultimately excreted from the body. The kidneys are important because they remove waste from the blood, they secrete various hormones, and they keep the blood well balanced in terms of electrolytes and sodium. The role of the efferent arterioles is to take blood away from the glomerulus, which is a bundle of capillaries attached to the kidneys. In conjunction with the afferent arterioles, which supply blood to the glomerulus, the efferent arterioles are responsible for constricting and dilating in order to control the blood flow to the kidneys.