American Urological Association - Kidney: Juxtaglomerular Apparatus
Kidney: Juxtaglomerular Apparatus
- Located at the vascular pole of the glomerulus.
- 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.
- Macula densa
- 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).