Kidney in cut-away view with a close-up on the glomerulus. At the extremity of each nephron there is the renal glomerulus, filtration unit of the kidney. The glomerulus includes the afferent glomerular arterioles, the efferent glomerular arterioles and is envelopped by the Bowman capsule. See. image 8124206 for the drawing of the glomerulus alone.