Histology of kidney.pptx

HISTOLOGY OF KIDNEY

1. HISTOLOGY OF KIDNEY Submitted By- Uttaran Modhukalya M.Sc. 4 th Semester, Zoology Dept., Brahmaputra college

2. CONTENT Introduction Cortex and Medulla Nephron Renal capsule Glomerular Filtration Renal tubule system Collecting system Blood suply Conclusion Histological picture of Kidney.

3. Introduction The kidneys are paired retroperitoneal organs of the urinary system. This organ filter blood and produce urine. It consist of cortex, medulla and calyces. The Kidney is a bean shaped, convex lateral surface, concave in medial surface Hilum is passage way for renal vessels and the ureter . Renal capsule cover the kidney. Renal fascia is the outermost layer and perirenal fat capsule is the intermediate layer.

4. Cortex and medulla Cortex is the Outer layer of kidney. It is darker than medulla due to receive 90% of the kidney blood supply. Cortex is grainy appearance, contain ovoid , coiled parts of the nephron. Medulla appears striped, having vertical nephron structure, renal pyramids. The apices of the pyramid projects towards the renal pelvis & open into minor calyces. Each renal pyramid with above cortical tissue form renal lobe. The renal lobule containing nephron that are served by common collecting duct.

5. NEPHRON It is the functional unit of kidney. Ultrafiltrate blood & form urine. Consist of renal corpuscle(located at cortex) and renal tubule system(extend into medulla). Nephron are cortical(corpuscle close to the kidney capsule) and juxtamedullary (close to corticomedullary border) types. Afferent arteriole enter to nephron and form capillary tuft( glomerulus ) then exit as efferent arteriole. Then continue to surround as peritubular capillary forming vasa recta around the nephron loop.

6. RENAL CORPUSCLE Consist Glomerulus and Bowman’s capsule. Glomerulus consist of parietal & visceral layer made up of podocyte . Outer parietal is made up of simple squamous . Afferent & efferent arteriole pole is vascular pole and opposite narrow glomerular thick segment pole is urinary pole.

7. Gloerular filtration Systemic blood passed through the glomerular capillary system & form ultrafiltrate( primary urine). This ultrafiltrate collected by glomerular space and passes into kidney tubule. Kidney filtration apparatus is formed by three layers of basal membrane ( a thick central lamina densa and two thin layer lamina rara interna and lamina rara externa .)

8. Renal Tubule system It has three parts where reabsorption of necessary molecule occurs and secreting waste substance. Proximal tubule : convoluted proximal tubule & straight proximal tubule( thick descending limb) Nephron loop : Descending and ascending loop Distal convoluted tubule : Straight distal tubule and convoluted distal tubule. Nephron loop is made up of simple squamous epithelium.

9. COLLECTING SYSTEM Series of tube that move the urine from the nephron to the minor calyces. Collecting duct travel through the kidney medulla converging at the apex of each renal pyramid. Juxtaglomerular apparatus: Formed by macula densa, juxtaglomerular granular(JG) & extra glomerular mesangial ( Lacis ) cells. It regulate the glomerular blood flow and filtration rate & systemic blood pressure.

10. BLOOD SUPPLY

11. CONCLUSION From the above discussion we can conclude that kidney is responsible for urine formation by filtration, reabsorption and secretion process. Functional unit of the kidney is nephron . Cortex, medulla, hilum , calyces are the major parts of the kidney which are covered by the renal capsule.

12. histological picture of KIDNEY

13. THANK YOU