JUXTA GLOMERULAR apparatus

DETAILED SLIDE OF JUXTA GLOMERULAR apparatus

1. JUXTA GLOMERULAR APPRATUS AND TUBULOGLOMERULAR FEEDBACK MECHANISM NEERAJ SHARMA ROLL NO-49 BATCH 2017-18

2. CONTENTS JUXTA GLOMERULAR APPRATUS(JGA) FUCTION OF JGA TUBULO GLOMERULAR FEEDBACK MECHANISM BIBLIOGRAPHY

3. JUXTAGLOMERULAR APPRATUS JGA is a combination of specialized tubular and vascular cells located near the glomerulus of each nephron JGA is formed by three different structures Macula densa cells Extra glomerular mesangial cells Juxtaglomerular cells

4. JUXTAGLOMERULAR APPRATUS

5. MACULA DENSA These are specialized renal tubular epithelial cells. Situated between afferent & efferent arterioles of the same nephron. Macula densa plays important role in tubulo -glomerular feedback mechanism. These cells are not innervated.

6. EXTRAGLOMERULAR MESENGIAL CELLS These cells are also called agranular cells,lacis cells These cells are situated in the triangular region bound by afferent arteriole , efferent arteriole & macula densa cells These cells play important role in the regulation of glomerular filtration by their contractile property These cells are phagocytic in nature

7. JUXTAGLOMERULAR CELLS Myoepithelial cells(modified vascular smooth muscle cells) called JG cells Also called granular cells because presence of secretory granules in their cytoplasm JG cells are well developed golgi apparatus and endoplasmic reticulum and ribosomes JG cells act as baroreceptors and innervated by sympathetic nerve fibers

8. FUCTION OF JGA Primary function of JGA is secretion of hormones It also regulates blood flow and GFR Secretion of hormone- Renin Prostaglandins

9. Renin- It is a peptide with 340 amino acids Along with angiotensin , renin forms RAAS Plays an important role in the maintainace of blood pressure Prostaglandin Secreted by interstitial cells of medulla JGA secretes cytokines like interlukin-2 and tumor necrosis factor.

10. REGULATION OF GLOMERULAR FLOW AND GFR Macula densa of JGA plays important role in feedback mechanism called tubuloglomerular feedback mechanism which regulate the renal blood flow and glomerular filtration rate

11. TUBULOGLOMERULAR FEEDBACK MECHANISM Tubuloglomerular feedback is the mechanism that regulate GFR through renal tubule & macula densa Macula densa detects the NaCl concentration via Na + K+ 2Cl-Cotransporter Adenosine acts on afferent arteriole via adenosine A1 receptors

12. FACTORS AFFECTING THE SENSTIVITY OF TGF INCREASE ADENOSINE THROMBOXANE PROSTAGLANDIN DECREASE ANP PROSTAGLANDIN CYCLIC AMP NITROUS OXIDE

13. BIBLIOGRAPHY Guyton and Hall Textbook of Medical Physiology E-Book (Guyton Physiology ) Google TEXTBOOK OF PHYSIOLOGY BY AK JAIN 4 . Ganongs Review Of Medical Physiology 25th Edition