Permeability of the Tubular System HO Nacl Urea Thin descending +十 limb Thick ascending Actively transport limb Thin ascending limb Distal tubule + ADH Actively transport Cortical + ADH Actively transport collecting duct Inner medullary + ADH Actively transport++ collecting duct
Permeability of the Tubular System H2O NaCl Urea Thin descending limb ++ _ _ Thick ascending limb _ Actively transport _ Thin ascending limb _ + + Distal tubule + ADH Actively transport _ Cortical collecting duct + ADH Actively transport _ Inner medullary collecting duct + ADH Actively transport ++
Formation of osmotic Gradient of the renal medulla ☆ The countercurrent theory 1. Countercurrent M multiplication逆流倍 增 与星
❖ The countercurrent theory ➢ 1. Countercurrent multiplication逆流倍 增 A B C Formation of Osmotic Gradient of the Renal Medulla Na+ H2O
1. Countercurrent multiplication Interstitial fluid osmolality NaCl H2O - NoCI 300 Nac M2 HO 60 H2 NoCI HO 1200 Nac H O H2O
1.Countercurrent multiplication Na+ H2O
Establishing of Osmotic Gradient of the Rena/Med∥l s Outer medulla (1 Proximal tubule 4 Distal tubule Nacl Nutrients H O reabsorption of Nacl at cOHO个K Nac HCO hick ascending limb→ hyperosmolality CORTEX 2 Descending tHick segment limb of of ascending e Inner medulla op of Henle NaCl HO 1)urea recycling OUTER Nacl MEDULLA 2)reabsorption of NaCl 3 Thin segment6Collecting of ascending at thin ascending Urea Nacl H2o limb-> hyperosmolality MEDULLA
Establishing of Osmotic Gradient of the Renal Medulla Outer medulla: reabsorption of NaCl at thick ascending limb → hyperosmolality Inner medulla: 1) urea recycling 2) reabsorption of NaCl at thin ascending limb→ hyperosmolality
Urea recvcling Urea Urea buchu inme dulla HO Increased osmolarity I.O medulla Urea Ureal H2O Favors nore Diffusion back water reabsorption into tubule T rea