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💀anatomy and physiology i review

Extraglomerular Mesangial Cells

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Extraglomerular mesangial cells are specialized cells located outside the glomerular tuft within the kidney's renal corpuscle. These cells play a crucial role in regulating the function and structure of the glomerulus, the filtration unit of the nephron.

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5 Must Know Facts For Your Next Test

  1. Extraglomerular mesangial cells are located in the extraglomerular mesangium, the region surrounding the glomerular tuft.
  2. These cells have contractile properties and can regulate the blood flow and filtration rate within the glomerulus.
  3. Extraglomerular mesangial cells secrete various signaling molecules, such as growth factors and cytokines, which influence the function and structure of the glomerulus.
  4. They play a role in the maintenance of the glomerular basement membrane and the regulation of the mesangial matrix within the glomerulus.
  5. Dysfunction or abnormalities in extraglomerular mesangial cells have been associated with the development of glomerular diseases, such as glomerulonephritis and diabetic nephropathy.

Review Questions

  • Describe the location and function of extraglomerular mesangial cells within the renal corpuscle.
    • Extraglomerular mesangial cells are located in the extraglomerular mesangium, the region surrounding the glomerular tuft within the renal corpuscle. These specialized cells play a crucial role in regulating the function and structure of the glomerulus, the filtration unit of the nephron. Extraglomerular mesangial cells have contractile properties, allowing them to control blood flow and filtration rate within the glomerulus. They also secrete various signaling molecules, such as growth factors and cytokines, which influence the maintenance of the glomerular basement membrane and the regulation of the mesangial matrix.
  • Explain the significance of extraglomerular mesangial cells in the development of glomerular diseases.
    • Dysfunction or abnormalities in extraglomerular mesangial cells have been associated with the development of various glomerular diseases. These cells play a critical role in maintaining the structural and functional integrity of the glomerulus. Disruptions in the contractile properties, signaling, or secretory functions of extraglomerular mesangial cells can lead to alterations in glomerular blood flow, filtration rate, and the composition of the mesangial matrix. This can contribute to the pathogenesis of conditions such as glomerulonephritis, where inflammation and damage to the glomerular structures occur, and diabetic nephropathy, where chronic hyperglycemia and metabolic changes impair the normal function of extraglomerular mesangial cells.
  • Analyze the relationship between the location and function of extraglomerular mesangial cells within the renal corpuscle and their role in regulating glomerular homeostasis.
    • The strategic location of extraglomerular mesangial cells in the extraglomerular mesangium, surrounding the glomerular tuft, allows them to play a pivotal role in maintaining glomerular homeostasis. These cells, with their contractile properties, can regulate the blood flow and filtration rate within the glomerulus, ensuring optimal perfusion and filtration efficiency. Additionally, the secretion of signaling molecules by extraglomerular mesangial cells influences the structural integrity of the glomerular basement membrane and the composition of the mesangial matrix, which are critical for the proper functioning of the glomerular filtration barrier. By integrating these regulatory functions, the extraglomerular mesangial cells contribute to the overall maintenance of glomerular health and the prevention of glomerular diseases.