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泌尿系统. urinary system. 杨志文. introduction. Component : 肾( kidney ): produce urine * 输尿管( ureter ) 膀胱( bladder ) 尿道( urethra ). -cavity organs, conduct, store and remove the urine. Functions : 1. elimination of metabolic waste products from the blood
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泌尿系统 urinary system 杨志文
introduction Component: 肾(kidney):produce urine* 输尿管(ureter) 膀胱(bladder) 尿道(urethra) -cavity organs, conduct, store and remove the urine
Functions: 1.elimination of metabolic waste products from the blood and their excretion in urine 2. regulation of water content, mineral composition, and acidity of the body 3.endocrine function (1) erythropoietin (controls erythrocyte production), (2) renin (generates angiotensin 1 from angiotensinogen and controls blood pressure and sodium balance), (3) 1αhydroxylase enzyme (metabolism of vitamin D), (4) prostaglandins (vasodilator effect)
kidney bean-shaped hilum:BV, LV, N and ureters enter or out
kidney capsule:DCT(纤维膜) interstitium:少量结缔组织、血管、神经 parenchyma: renal cortex:dark stained 髓放线(medullary ray) 皮质迷路(cortical labyrinth) 肾柱(renal columns of Bertin) renal medulla:slight stained 肾锥体(renal or medullary pyramids) 肾门(renal hilum)、肾叶(lobe)、肾小叶(lobule)
血管球 肾小体 肾小囊 肾单位 泌尿小管 肾小管 集合小管 曲部 远端小管 曲部 近端小管 集合管系 皮质集合管 直部 直部 细段 髓质集合管 乳头管 髓袢 Kidney contains numerous uriniferous tubules, which are composed of nephrons and collecting tubules.
parenchyma:泌尿小管(uriniferous tubule) 肾单位(nephrons)←生后肾组织 肾小体:血管球+ 肾小囊 肾小管: 近端小管:曲部 直部 细段 远端小管:直部 曲部 集合管系(collecting tubules)←输尿管芽 集合小管(collecting tubule) 皮质集合管(cortical collecting duct ) 髓质集合管(medullary collecting duct) interstitium:CT, BV, N…… 髓袢(medullary loop, Henle loop, nephron loop)
肾单位(nephron) About 1~4 million per kidney. The structural and functional unit of kidney. 肾小体(renal corpuscle) 肾小管(renal tubule) 根据肾小体在皮质中的位置 髓旁肾单位 (juxtamedullary nephron) 浅表肾单位 (superficial nephron)
juxtamedullary nephron superficial nephron 发生早 发生晚 靠近肾锥体 位于皮质浅层 体积大 体积小 数量少,占 15%数量多,占 85% 髓袢长 髓袢短 尿液浓缩 尿液形成
renal corpuscle spherical, 200µm in diameter The place where the blood is filtered to form pre-urine. 血管极(vascular pole) where the afferent arteriole enters and thinner efferent arteriole leaves renal corpuscle. 尿极(urinary pole) where the proximal convoluted tubule begins. 血管球(renal glomerulus) 肾小囊(renal capsule)
renal glomerulus The glomerulus derived from the afferent arteriole and drained by efferent arteriole. 特点: 1、the efferent arteriole is thinner than afferent arteriole. 2、fenestrated capillary without diaphragm
mesangium 又称球内系膜(intraglomerular mesangium) 系膜细胞(mesangial cell) small, irregular, with processes (1) produce ground substance (2) phagocytosis---参与基膜更新 (3)contract---调节血流量 (4)secrete renin and enzymes 系膜基质(mesangial matrix) 填充在系膜细胞之间,支持、通透 type IV collagen, glycoprotein
renal capsule 1.double layered capsule 2.formed by beginning part of renal tubule which is enlarged and invaginated 壁层(parietal layer):simple squamous epithelium (与近端小管上皮在尿极处相延续) 脏层(visceral layer):足细胞(podocyte) 初级、次级突起(primary and secondary process) 裂孔(slit pore)、裂孔膜(slit membrane) 肾小囊腔(capsular space):含原尿
足细胞的功能 1.参与血管球基膜(GBM)的形成和更新 2.活跃的胞吞活动 3.对血管球毛细血管的支持作用 4.调节血管球的滤过率 5.免疫学功能……
滤过膜(filtration membrane) (滤过屏障filtration barrier) 1.fenestrated endothelium(negative ions) 2.基膜(basement membrane) EM:内疏层(lamina rara interna) 致密层(lamina densa) 外疏层(lamina rara externa) 由Ⅳ、Ⅴ、Ⅵ型胶原蛋白、层粘连蛋白、蛋白多糖组成。 其糖胺多糖以硫酸肝素为主,它们共同形成有4-8nm 孔径 的分子筛(laminin-negative ions) 3.slit membrane(negative ions)
由 单 层 上 皮 围 成 的 小 管 renal tubule
renal tubule proximal convoluted tubule Henle’s loop proximal straight portion thin segment distal straight portion distal convoluted tubule
proximal convoluted tubule structure: LM EM 1.simple cuboidal or pyramidal 2.no clear boundary lateral process 3.eosinophilic 4.free surface:brush border microvilli apical canaliculi 5.basal region:longitudinal striation plasma membrane infolding (mitochondria) (rich in Na+-K+ ATPase)
proximal convoluted tubule function: 1.reabsorption:全部葡萄糖、氨基酸,85%水 65%Na+,50%尿素 2.excretion:氢,氨,肌酐,马尿酸 3.transfer:酚红、青霉素等
细段(thin segment) 1.simple squamous epithelium 2.facilitate the passage of water and ions
distal tubule 直部(distal straight portion) LM:1.上皮细胞立方形,分界清,着色浅,核圆居中 2.细胞表面无刷状缘,基底可见纵纹 EM:游离面:少量微绒毛 基部:质膜内褶发达(线粒体、钠泵) 曲部(distal convoluted tubule) 保钠、排钾、泌氢、泌氨——离子交换、维持酸碱平衡 受醛固酮 aldosterone、抗利尿激素 antidiuretic hormone(ADH)的调节——浓缩尿液
集合管(collecting duct) 集合小管、皮质集合管、髓质集合管 结构:LM:simple columnar, distinct boundary, clear cytoplasm 主细胞(principle cell) 闰细胞(intercalated cell) EM:少量微绒毛、少量侧突、短小质膜内褶 功能:进一步重吸收水、交换离子,使原尿进一步浓缩。 受醛固酮、抗利尿激素、心房钠尿肽调节。
远端小管直部 T-H蛋白 不透水 肾小体形成的原尿在流经肾小管各段和集合管时,其中葡萄糖等成分和99%的水均被重吸收,同时由小管上皮细胞分泌部分物质,最终仅1%左右的原尿作为终尿(约1-2L/天)排出体外。
球旁复合体( juxtaglomerular complex) (肾小球旁器juxtaglomerular apparatus) Locate at vascular poles. 球旁细胞 致密斑 极垫细胞 极周细胞