Urinary System 泌尿系统

1. Urinary System泌尿系统 Xue Zhou Department of Histology & Embryology, Sichuan University

2. Function 1. Excretion metabolic waste products 2. Maintaining the balance of fluid and electrolyte 3. Secretion of some substances

3. Composition Kidney----main organ Ureter Excretory ducts Urinary bladder Urethra

4. Kidney 肾 Structure bean shaped Nephron---function unit Parenchyma Collecting tubule Interstitial tissue: a little loose connective tissue

5. medullary ray Cortex cortex cortical labryinth renal column minor calyx major calyx renal pyramid (Medulla) renal pelvis renal papilla ureter Renal corpuscle Nephron Renal tubule Uriniferous tubule Collecting tubule

6. Nephron 肾单位 // The structural & functional unit; // Include renal corpuscle, proximal tubule, thin segment , distal tubule; // Produce urine. Proximal straight tubule Henle’s loop Thin segment Distal straight tubule

7. Structure and function of each segment ① Renal corpuscle 肾小球 Function: filtration of blood plasma to form primary urine.

8. Structure spherical body Renal glomerulus Renal capsule Vascular pole Urinary pole

9. Renal corpuscle, HE

10. Renal glomerulus, SEM

11. A. Renal glomerulus 肾血管球 √afferent arteriole √efferent arteriole Which one should be thicker? Why? √capillary ----- which type? fenestrated capillary

12. Fenestrated capillary & Podocytes

13. B. Renal capsule( a double layered capsule) 肾小囊 ·Parietal layer 壁层: simple squamous epi connect with proximal tubule ·Visceral layer 脏层: podocytes（足细胞）, primary & secondary process, filtration slit

14. Fenestrated capillary & Podocytes

15. Fenestrated capillary, TEM

16. Filtration barrier, TEM

17. Filtration barrier滤过屏障 // The structure separate the cap blood from the capsular space. // It consists of fenestrated endothelial cell, basement membrane & filtration slit membrane. // Filtrate blood plasma to form primary urine.

19. slit water B.M cation Endo. glucose anion 白蛋白 protein

20. nutrients: glucose, amino acids… Primary urine waste products 180L/day water electrolytes A lot of nutrients, water, electrolytes will be reabsorbed by following segments.

21. ② Proximal tubule 近端小管 the largest, longest segment of nephron Function: reabsorption --- 85%H2O, NaCl, all G, AA, proteins excretion--- H+, NH4+…

22. Proximal convoluted tubule

23. Proximal convoluted tubule, EM

24. Proximal convoluted tubule 近曲小管: simple cuboidal epi with classical structure of reabsorption. EM LM Free surface microvill,tubular pits brush border Lateral margin lateral process unclear border Basal end infolding,mitochondria basal striations All above increase the surface of cell greatly,permit reabsorbing rapidly from tubule lumen and giving away reabsorbing substances to interstitial tissue quickly.

25. ③ Thin segment 细段 Small sized tubule line with simple squamous epithelium. Function: urine concentration by it’s thin wall and hyperosmat of medullary interstitial tissue.

26. ④ Distal tubule 远端小管: Simple cuboidal epithelium. This segment is thinner and shorter than proximal tubule. Function: In the influence of aldosteron(醛固酮) regulate the acid-base equilibrium of body: reabsorption Na+, Cl- and water; excretion K+, H+, NH4+ .

27. ⑤ Collecting tubule 集合小管 Simple cuboidal or columnar epithelium. LM: lumen--- largest cytoplasm--- lightest cell border--- clearest Function: collecting urine of nephron, regulating the concentration of urine as distal tubule.

28. Juxtaglomerular apparatus 球旁复合体

29. ①Juxtaglomerular cell 球旁细胞 *Modified smooth muscle cells in the wall of afferent arteriole. *Large and pale epitheoid cells *Secretion rennin(肾素) into blood for regulation the blood pressure and the function of distal & collecting tubule.

30. ②Macula densa 致密斑 *The epithelium of distal tubule become columnar and form a elliptic spot. *Sense the urine Na+ concentration in lumen & influence the function of Juxtaglomerular cell.

31. ③Extraglomerular mesangial cell 球外系膜细胞 A group of cells, lying between the macula densa & afferent, efferent arterioles. The function is not well understood.

32. I. The Development of Urinary System nephrotome,nephrogenic cord urogenital sinus pronephros mesonephros urinary bladder and urethra metanephros (epithelium) (permanent kidney)

34. The Metanephros 5th week caudal to the mesonephros permanent functional ureteric bud two sources metanephric mesoderm

38. mesonephric ductmetanephric mesoderm ureteric bud metanephric tubules ureter, renal tubules renal pelvis, major & minor calyces, collecting tubules one end another end communicate invaginated by capillaries collecting tubule nephron

39. Horse-shoe Kidney Ectopic Kidney

40. Ectopic Kidney

41. Horse-shoe kidney

42. Polycystic kidney

43. Polycystic kidney

44. Double Ureters

45. Double Ureters

46. Double ureters