1 / 50

Histology Lecture 17 Urinary System

Histology Lecture 17 Urinary System. Urinary System. The urinary system is composed of: Kidneys Ureters Bladder Urethra. Kidney. Hilum where Nerves, vessels enter and exit Ureter exits Ureter expanded here and form renal pelvis 150g. Kidney. Thin renal capsule Cortex Medulla:

Download Presentation

Histology Lecture 17 Urinary System

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. HistologyLecture 17 Urinary System

  2. Urinary System The urinary system is composed of: • Kidneys • Ureters • Bladder • Urethra

  3. Kidney • Hilum where • Nerves, vessels enter and exit • Ureter exits • Ureter expanded here and form renal pelvis • 150g

  4. Kidney • Thin renal capsule • Cortex • Medulla: • Pyramids: 10-15 • Renal papillae (ducts of Bellini) • Adjacent pyramids separated by material like the corex, known as cortical column (of Bertin)

  5. Kidney • Three type of substances observed in the cortex • Renal corpuscles ( Red dot-like granules) • Cortical labyrinth (Convoluted tubules) • Medullary rays (Longitudinal striations) • Medullary rays • Kidney lobe • Kidney lobule

  6. Uriniferous Tubules Uriniferous Tubules is the functional unit of the kidney, composed of a nephron and a collecting tubules Nephron • About 2 million in each kidney • Nephron is composed of • Renal corpuscle with glomerulus • Proximal convoluted tubule • Thin & thick loops of Henle • Distal convoluted tubule • 2 different types of nephrons: cortical & juxtamedullary

  7. Renal Corpuscle • It is an oval to round structure that has about 0.2mm • Composed glomerulus • Bowman’s capsule • visceral layer • Parietal layer • Urinary space • Has 2 pole

  8. 45 - 20 - 10 =15

  9. 100 nm 6 nm 25 nm

  10. Mesengial cells Contractile like Pericytes Receptor for Ang.II & NF Structural support Secretion of ECM Endocytosis like macrophage

  11. PCT

  12. Proximal Convoluted Tubule PCT • Simple cuboidal epithelium • Thick brush border, intricate lateral border processes, and basement membrane • Acidophilic cytoplasm • Absorb macromolecules from glomerular ultra filtrate, and some ion transport • 67% to 80% of Na, Cl and water • All glucose, amino acids and proteins resorbed • Secretion of Cratinine, H+ • Produce Vit D

  13. Loop of Henle

  14. Loop of Henle • Loop of Henle has 15-20 micrometer in diameter composed of simple squamous cells • Thick descending limb similar to PCT, Thin descending limb, Thin ascending limb, Thick ascending limb similar to distal convoluted tubule • Thin segment in cortical nephron is short (1-2mm) but long in juxtamedullary (10 mm) so extended deep into medulla and make Henle’s loop • Thin limb resemble capillaries in sections • Thin limb has short microvilli, basal process that interdigitate with adjacent cells • Descending thin limb is highly permeable to water and so to urea NaCl and other ions

  15. Distal Convoluted Tubule • It has 2 parts: pars recta and pars convoluta • It is lined by ? • Narrower cells • Have Na-K pumps that respond to Aldosterone • secretes H+ and NH4+ into tubular urine • Macula densa region near glomerulus

  16. Macula Densa • Macula densa is a specialized region of DCT • Cells sensitive to Cl inside tubule • When Cl is high ,causes contriction of afferent arteriole • Also may regulate renin release by juxtaglomerular cells

  17. Macula Densa & DCT

  18. Juxtaglomerular Apparatus • Juxtaglomerular apparatus has 3 components: • Macula densa • Juxtaglomerular cells of afferent arteriol • Extraglomerular mesangial cells( polkissen or lacis cell)

  19. Collecting Tubules and Ducts • Collecting tubules and ducts are not part of nephron • Collecting tubules • Principal cells reabsorbing H2O & Na • Intercalated cells(dark cell) with apical vesicles, reabsorbing K, secretion of H or HCO3 • Papillary collecting ducts(ducts of Bellini) 200 to 300 µm open at area cribrosalined by tall columnar principal cells only • ADH

  20. Renal interstitium • Cortex loose CT housing fibroblasts and macrophages • Medulla loose CT housing fibroblasts, macrophages, and interstitial cells • Interstitial cells numerous between ducts of Bellini • These cells have elongated nuclei and many lipid droplet • These cells Synthesize of Medullipin I converted by liver to Medullipin II a vasodilator

  21. Renal Circulation

  22. Calyx • The renal papilla fits into minor calyces, this portion of papilla lined by transitional epithelium • Epithelium is supported by loose CT of lamina propria, deep to it there is a coat of smooth muscle cells Ureter • Mucosa with several folds composed of transitional epithelium 3-5 cell layers supported by a dense irregular CT(lamina propria) • Smooth muscle: inner longitudinal , and outercircular layers, in distal one third an outer longitudinal layer added to other two layers • Fibrous outer coat of CT is not remarkable

  23. Bladder • Mucosa lined with transitional epithelium • Plasmalemma of surface epithelial cells composed of mosaic of specialized, rigid, thickened regions known as plaques that lie between normal cell membrane (interplaque regions) • Tight junctions and desmosomes between cells seal paracellular pathways • Lamina propria of dense irregular CT • Smooth muscle runs in random directions except at neck where 3 layers may be detected: inner longitudinal, middle circular and outer longitudinal layers • Outer adventitia or serosa • Urethra is covered in reproductive system lectures

  24. Department of Anatomical Sciences Arak Medical University M. Bayat 88/2/19 88/10/2 89/2/25 90/9/28 94/2/28 94/2/29

More Related