Glomerulus The glomerulus (or renal corpuscle) consists of the glomerular capillaries and the epithelium-lined sac that surrounds and invests them, known as Bowman’s capsule. The glomerular capillaries originate from the afferent arteriole and drain into an efferent arteriole. They are arranged in a tuft about 200 µm in diameter, which is anchored to a central stalk of mesangial cells and matrix. The walls of the glomerular capillaries contain three layers. The innermost layer consists of…