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
1. Macula densa cells
2. Extra glomerular mesangial cells
3. 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-
1. Renin
2. 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.

11. 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

12. 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

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

14. • INCREASE IN GFR
• INCREASE IN NACL CONCENTRATION IN RENAL TUBULE
• DETECTION OF NACL BY MACULA DENSA
• ADENOSINE
• CONSTRICTION OF AFFERENT ARTERIOLE
• DECREASE IN GLOMERULAR BLOOD FLOW
• TUBULOGLOMEULAR FEEDBACK
• WHEN GFR DECRESE
• CONC. OF NACL DECRESASE IN FILTRATE
• MD SECRETES PROSTAGLADIN,BRADYKININ,RENIN
• PGE2,BRADYKININ CAUSE DILATION OF AFFERENT ARTERIOLES
• RENIN CAUSE CONSTRICTION OF EFFERENT ARTERIOLES
• INCRESE IN GLOMERULAR BLOOD FLOW AND GFR

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