1. Chapter 16 Urinary System Chapter 16 Urinary System

2. 1.Components ---kidney : produce urine ---ureter ---bladder cavity organs(conduct, store and ---urethra remove the urine) ---functions: remove waste products of metabolism regulate the homeostasis secrete some bioactive factors---renin and erythropoietin

3. 2. Kidney ---bean-shaped ---hilum: BV, LV, N and ureter enters or out * renal pelvis: expansion of upper end of ureter calyx: branches of renal pelvis *

4. 1) General structure: ---capsule: DCT ---cortex: /medullary rays /cortical labyrinth ---medulla: /renal pyramid /renal columns /renal papillae

5. cortexmedulla

6. renal parenchyma mainly consists of uriniferous tubules ---uriniferous tubule is composed of nephron and collecting tubule ---nephron is composed of renal corpuscle and renal tubules ( cortical and juxtamedullary nephron)

7. 2) Nephron: structural and functional unit (1,000,000) ---renal corpuscle: /renal glomerulus /renal capsule ---renal tubule: /proximal tubule (red) --convoluted portion --straight portion /thin segment (blue) /distal tubule (orange) --straight portion --convoluted portion cortex medulla

8. ① renal corpuscle : spherical, 200um in D, two poles: vascular pole and urinary pole ---glomerulus: afferent arteriole→capillary network→efferent arteriole ---renal capsule

10. *intraglomerular mesangium: located among capillaries /mesangial cell: -small, irregular, with processes -small dark N its functions: i. produce ground substance ii. phagocytosis iii. contract iv. secrete renin and enzymes /matrix: fills the space among the mesangial cells -type IV collagen -glycoprotein

11. ---renal capsule : two layers formed by beginning part of renal tubule which is enlarged and invaginated /parietal layer: simple squamous epi. /visceral layer: podocytes parietal visceral

12. foot process: interdigitate each other and embraced the capillaries slit pore: narrow intercellular space (25 nm)between foot processes with 4-6 nm diaphragm-slit membrane podocyte : cells with many processes primary process secondary process (foot processes)

13. filtration barrier: the structure for filtration. including: fenestrated endothelial cell basal lamina slit membrane selective filter: prevent proteins with negative ions and huge molecules from passing it.

14. ② renal tubule: a.proximal tubule: LM: pyramidal cuboidal eosinophilic round N brush-liked border longitudinal striation no clear boundary

15. EM: microvilli plasma membrane infolding lateral extension

17. ---Function: i. reabsorption : -85% Na + ions and water -All of glucose, amino acid, polypeptide, proteins and vitamin ii. secrete H +, NH 3, hippuric acid and creatinine

18. b. thin segment: /10-15 um, simple squamous epi, /facilitate the passage of water and ions /reabsorb Na + and Cl - and 5% water

19. c. distal tubule: ---structure: LM: cuboidal slight-stained round N no brush-liked border well-developed longitudinal striation

20. EM: less microvilli more plasma membrane infolding

21. ---function: i. reabsorption of 8% water, Na + ions ii. excretion of K +, H +,NH 3 iii. regulated by aldosterone (adrenal gland) and vasopressin (pituitary gland)

22. 3) collecting tubule : arched collecting tubules cortical collection tubules medullary collection tubules -simple cuboidal epi. to simple columnar epi. -slight – stained -have clear boundary -reabsorb 4% water

23. 4) juxtaglomerular complex juxtaglomerular cell macula densa extraglomerular mesangial cell ---function: regulate the reabsorption and secretion of renal tubule

24. a. juxtaglomerular cell: ---a groups of modified SM cell of afferent arterioles ---structure: -larger, cuboidal in shaped, with round N -contain secretory granules ---function: i.secrete renin to make blood pressure↑ ii. secrete erythropoietin to promote erythropoiesis

25. b. macula densa -a group of cells derived from epi. of distal tubule -cell becomes taller, narrow, with round N apical part arranged -cells have processes connecting with other cells ---function: chemoreceptors- feel the Na+ ions concentration

26. c.extraglomerular mesangial cell (polar cushion cell) ---similar to intraglomerular mesangial cell ---transfer the information

27. cavity organs (ureter and bladder): mucosa: /epi-transitional epi /lamina propria muscularis: SM adventitia: CT