Consists of the afferent arteriole (AA) right before it enters the glomerulus, and a portion of the distal convoluted tubule (DCT) of the same nephron, which loops back and lies against the afferent arteriole at this point (image A) & (image B).
Regulate systemic blood pressure via Renin-Angiotensin-Aldosterone system.
Contains 3 cell types:
Juxtaglomerular cells (JG cells or granular cells)
Specialized smooth muscle cells with granular cytoplasm (renin production) and prominent nucleus.
Form a cuff of several layers around the AA just before it enters the glomerulus.
Consists of modified DCT cells, which are taller and have larger more prominent nuclei than adjacent cells.
Lacis cells (cells of Goormaghtigh)
Extraglomerular mesangial cells.
Unknown function (may secrete erythropoietin).