American Urological Association - Kidney: Juxtaglomerular Apparatus


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Kidney: Juxtaglomerular Apparatus

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Image B

  • 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).