Urinary system

Urinary System

General outline component urinary organs: kidneys micturition organs: ureter, bladder and urethra function discharge metabolite regulate the balance of water and electrolyte endocrine function: renin, erythropoietin, prostaglandin

肾素 renin 的作用 作用：分泌肾素 renin 血管紧张素原 促肾上腺皮质 分泌醛固酮 血管紧张素Ⅰ 促进肾小管和集合管 保钠、排钾、保水 血管紧张素Ⅱ 血容量增加 血压升高

Renal anatomic structure Fibrosa Cortical labyrinth Medullary ray Cortex Parenchyma Renal pyramids Renal columns Medulla

Renal histological structure Glomerulus Bowman’s capsule Renal corpuscles nephron Renal tubules collecting duct juxtaglomerular apparatus

肾的一般结构 肾柱renal column：肾锥体之间的皮质 肾锥体：条纹状，尖朝肾小盏，底朝皮质。 肾皮质 皮质迷路 肾髓质 肾动脉 肾锥体 肾静脉 肾盂 肾大盏 肾小盏 肾被膜 肾柱renal column：肾锥体之间的皮质 肾锥体：条纹状，尖朝肾小盏，底朝皮质。 髓放线medullary ray：由肾锥体底部向皮质延伸的细线 皮质迷路cortical labyrinth：两条髓放线之间的皮质 皮质cortex：位于外周，包括肾柱、髓放线、皮质迷路 髓质 medulla：深部，由十多个肾锥体组成 被膜capsule：致密CT 肾柱 髓放线

肾叶renal lobe：一个肾锥体及与周围相连的皮质 肾小叶renal lobule：每根髓放线及周围的皮质迷路 肾小叶和肾叶 被膜 皮质迷路 髓放线 肾小叶 肾叶 肾叶renal lobe：一个肾锥体及与周围相连的皮质 肾小叶renal lobule：每根髓放线及周围的皮质迷路 肾锥体

㈠　肾单位（nephron）　 肾小体 肾小管 集合管 集合管 肾单位

肾实质： 泌尿小管 肾间质 泌尿小管： 肾小管 集合管 肾单位： 肾小球

二、肾 肾单位 肾小管 细段 近端小管 血管球 肾小体 肾小囊 泌尿小管 弓形集合小管 曲部 远端小管 曲部 集合小管 直部 直部 直集合管 乳头管 髓袢

Kidney

Renal cortex Renal medulla

Structure of Renal corpuscle: afferent arteriole efferent arteriole capillary network mesangial cells Glomerulus parietal layer: simple squamous Epi. Bowman’s capsule capsular cavity: filtrate visceral layer: podocytes (primary and secondary processes, slit membrane)

Renal corpuscle

Podocyte

Glomerulus Renal corpuscle

Functions of Renal corpuscle: Produce filtrate (primary urine) fenestrated endothelium basement membrane slit membrane of podocyte Filtration membrane (filtration barrier) molecular weight charges relevant factors of filtrate

一般情况下，69kD的白蛋白可少量滤过，150~200kD的免疫球蛋白则阻止在基膜内。 滤过膜滤过作用与其结构和电荷有关 1、体积依赖性屏障作用： 一般情况下，69kD的白蛋白可少量滤过，150~200kD的免疫球蛋白则阻止在基膜内。 2、电荷依赖性屏障作用：滤过膜带负电荷

水肿 高血压 少尿、无尿 尿量 氮质血症 尿改变 多尿、夜尿 血尿 尿毒症 蛋白尿 尿质 管型尿

Filtration membrane

Endothelium GBM Epithelium Podocyte, Slit membrane Filtering membrane

球内系膜和系膜细胞 毛细血管之间，由系膜细胞和基质组成 系膜细胞形态： 不规则、有突起，核小色深，ＲＥＲ、高尔基复合体发达，溶酶体多。 系膜细胞功能： 合成基质和基膜 吞噬降解免疫复合物 更新和修复基膜 分泌生物活性物质。

Renal tubules: convoluted tubule straight tubule proximal thin segment Henle’s loops straight tubule convoluted tubule distal

Proximal tubule Location: cortical labyrinth LM: simple cuboidal or pyramid Epi. acidophilic cytoplasm no discrete cell margin; brush border; longitudinal striation

Convoluted segments of proximal and distal tubules

EM: apical canaliculi and vesicles numerous lysosomes, Mi. many lateral interdigitations microvilli on the surface membrane invaginations abundant Na+-K+ATPase

Function reabsorb water, glucose, amino acid, protein, vitamin and inorganic salts etc. secrete ammonia and some metabolic substances

thin segment location: medullary ray and renal pyramids LM: simple squamous Epi.; pale cytoplasm, EM: a few microvilli; less organelles Function: water, and ions pass through easily

Thin segment and straight segment of distal tubule

Distal tubule location: medullay ray and renal pyramids LM: simple cuboidal Epi; clear cell boundary; pale cytoplasm; nuclei near lumen; without brush border; have longitudinal striation

EM: a few microvilli; many membrane invagination; many mitochondria; abundant Na+-K+ATPase Function: reabsorb Na+ and water; excrete K+; secrete NH3

Distal straight tubules and collecting tubules

Convoluted segments of proximal and distal tubule

两种肾单位 皮质肾单位 近髓肾单位 比较表

两种肾单位的比较 皮质肾单位 浅表肾单位 近髓肾单位 髓旁肾单位 数量 多 少 位置 浅表 深部 肾小体大小 小 大 髓袢 短 长 功能侧重 尿液形成 尿液浓缩

Collecting tubules: location: medullary ray and renal pyramids components: arched collecting tubules; straight collecting tubules; papillary ducts simple cuboidal Epi simple columnar Epi., papillary ducts line tall columnar Epi; pale staining; distinct borders; rare microvilli and Mi. function: similar to that of distal convoluted tubules

Straight segment of distal tubule and collecting tubule

Juxtaglomerular apparatus: located in a triangle area at the vascular pole of the renal corpuscles consist of juxtaglomerular cells, macular densa and extraglomerular mesangial (polar cushion) cells function: control water and electrolyte balance; regulate blood pressure; produce erythropoietin

Juxtaglom-erular apparatus

Juxtaglomerular cells smooth muscle cells of the afferent arteriole transform into the epithelial cells cytoplasm: a few myofibrils; PAS-positive granules contained renin; abundant RER, ribosomes and well developed Golgi apparatus; function: secrete renin and erythropoietin

Juxtaglomerular cell

Macular densa transformed from the cells of distal tubule which near the vascular pole of the renal corpuscle the cells become taller and narrow, arranged compactly; pale cytoplasm; nuclei located at the apex a chemical (Na+ ) sensor

Macular densa

Extraglomerular mesangial cells resemble the intraglomerular mesangial cells gap junctions between the component of the juxtaglomerular apparatus transmit information

Features of renal blood circulation blood flow is large two sets of capillary network the diameter of afferent arterioles is larger than that of efferent, so as to facilitate filtration the vasa recta are parallel to the Henle’s loop, so aid water reabsorption and urine concentration

Blood vessels of kidney

Micturition organs (ureter, bladder,) Epi: transitional Epi Lamina propria: L.C.T. mucosa muscle layer: smooth muscle adventitia: fibrosa serosa

Bladder

Ureter

New Words 1. Kidney 2. Renal medulla 3. Renal cortex 4. Renal (medullary) pyramids 5. Renal papilla 6. Renal columns of Bertin 7. Medullary rays 8. Renal corpuscle: 9. Bowman’s capsule 10. Renal glomerulus 11. Proximal convoluted tubule

12. Loop of Henle 13. Distal convoluted tubule 14. Collecting tubules 15. Potocytes 16. Pedicels 17. Renal filtration barrier 18. Ureter 19. Urinary bladder 20. Urethra 21. Juxtaglomerular (JG) apparatus 22. Juxtaglomerular cells 23. Macula densa cells 24. Extraglomerular mesangial cells

谢 谢 ！