The human kidney consists of over one million, non-regenerative functional units called nephrons.
Nephrons are responsible for cleansing the blood of unwanted substances and for urine formation.
Each nephron contains a system of blood vessels and tubules. The blood vessels consist of the afferent arteriole, the efferent arteriole, the glomerular capillaries, and the peritubular capillaries. The two capillary beds are connected in series. The glomerulus consists of a network of glomerular capillaries with a glomerular membrane. The glomerular capillaries form a network of branching and anastomasing capillaries.