Definition of Juxtaglomerular apparatus

The juxtaglomerular apparatus is a microscopic structure in the kidney that regulates the function of each nephron, the functional units of the kidney. The juxtaglomerular apparatus is named because it is next to (juxta-) the glomerulus. The juxtaglomerular apparatus consists of three cells: 1. * the macula densa, a part of the distal convoluted tubule of the same nephron 2. * juxtaglomerular cells, which secrete renin 3. * extraglomerular mesangial cells
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