Histology of kidney B. Sc. II Dr. Manjiri A. More Department of Zoology GKG College Kolhapur

1. Histology of kidneyB. Sc. IIDr. Manjiri A. More Department of ZoologyGKG College Kolhapur

7. Renal hilum or hilus- with notch in which renal vessels, nerves and the ureter enter or leave the kidney. Renal capsule- - outer thick covering of kidney - consist collagane fibers, smooth muscle fibers, -Hilum is lined by invagination of the capsule

8. Medulla- • Contain 5-8 triangular renal pyramids • Tip of each renal pyramids continuous to renal papilla(striation of collecting ducts and blood vessels) • Apex is directed towards the cortex and base is directed toward the renal pelvis and fit in to minor calyx. • Minor and major calyces unit to form renal pelvis and continous in to ureter

9. Cortex • outer granular region • tissue lying between adjacent pyramids is a part of cortex and called renal columns. • from the base of pyramids, thin radically directed striations extend into cortex but not up to entire thickness of cortex • These called medullary rays or medullary rays of ferrin • Cortex is dark colored and granular appearance than medulla.

10. Histology of kidney

11. Histologically kidney shows the numerous uriniferous tubules. • These are functional unit of kidney is called nephron • These has following structure

13. Position of uriniferous tubules Cortex- malphian corpuscles, PCT and DCT Outer zone of medulla- henle loop and collecting tubules Inner zone of medulla- thin segment of henles loop, collecting ducts and ducts of bellini Microscopic study of renal tissue- large number of closely packed uriniferous tubules and blood vessels surrounded by scenty reticular fibers.

14. Is also called –malpighian body or bowmans capsule • Round body • Consist- two parts- • Central glomerulus- consisting of mesh of afferent and efferent arterioles. • Peripherial zone- • Separated by a space the bowmans capsule • Cells- • - Glomerular capillaries lined by- endothelial cells And perforated by podocytes. • Neck of bowmans capsule is lined by simple cuboidal ciliated cells Renal corpuscle

15. Podocytes Modified cells to form stellate cells Primary branches of these cells give rise to secondary branches called pedicles Pedicles rest on the capillary endothelium Between two pedicles or adjacent there is little pores known as filtration slits . These arrangement helps filtration of blood

16. Cells of tubules PCT lined by pyramidal cells with characteristic brush border called brush bordered cells Free surface has microvilli forming brush border Nucleus is large, spherical and basal The thick segment is lined by simple cuboidal epithelium Where as thin segment of loop of henle is lined by simple squmous epithelium cells

17. Distal convoluted tubules Lined by- columnar epithelium cells Without brush border Few microvilli are seen Cytoplasm is acidic Basal and lateral folding with many mitochondria are seen

18. Collecting tubule Collecting tubules and duct of bellini lined by simple columnar epithelium cells with cell boundary very well defined Nucleus is prominent These concern with selective reabsorption, active secretion and transport of urine