Kidney glomerulus

Glomerulus
Looped capillaries of glomerulus between the arterioles
Details
Precursor	Metanephric blastema
Identifiers
Latin	glomerulus renalis
MeSH	A05.810.453.324.359
Dorlands /Elsevier	g_07/12394744
FMA	15624
Anatomical terminology []

The glomerulus (/ɡləˈmɛr(j)ələs, ɡloʊ-/), plural glomeruli, is a network of capillaries known as a tuft, located at the beginning of a nephron in the kidney. The tuft is structurally supported by intraglomerular mesangial cells. The blood is filtered across the capillary walls of this tuft through the glomerular filtration barrier, which yields its filtrate of water and soluble substances to a cup-like sac known as Bowman's capsule. The filtrate then enters the renal tubule, of the nephron.

The glomerulus receives its blood supply from an afferent arteriole of the renal arterial circulation. Unlike most capillary beds, the glomerular capillaries exit into efferent arterioles rather than venules. The resistance of the efferent arterioles causes sufficient hydrostatic pressure within the glomerulus to provide the force for ultrafiltration.

The glomerulus and its surrounding Bowman's capsule constitute a renal corpuscle, the basic filtration unit of the kidney. The rate at which blood is filtered through all of the glomeruli, and thus the measure of the overall renal function, is the glomerular filtration rate (GFR).