Solute and water transport in the loop of Henle, distal tubule and cortical collecting tubule. Flashcards
descending limb - 1
- highly permeable to water
- impermeable to solutes na+/k+/cl-
descending limb - 2
when filtrate moves through descending limb, water gets reabsorbed into surrounding hypertonic interstitial fluid of medulla
filtrate gets more concentrated as it moves through medulla
ascending limb - 1
thick ascending limb
- impermeable to water so filtrate gets diluted as moves through the loop of henle
ascending limb - 2
thick ascending limb
- moves solutes by secondary active transport
- by sodium-potassium-chloride cotransporter from filtrate into TAL
- na/k ATPase pump takes sodium into interstitium forming a concentration gradient for sodium reabsorption
ascending limb - 3
filtrate gets diluted as nacl gets removed without water coming out
distal convoluted tubule - 1
sodium
- sodium reabsorbed by na+/cl- symporter + na/k ATPase pump
- enhanced by aldosterone
distal convoluted tubule - 2
potassium
secreted into filtrate in exchange for sodium
distal convoluted tubule - 3
calcium
- calcium reabsorbed in exchange for sodium by sodium/ calcium exchanger _ calcium channels
- under regulation of PTH
distal convoluted tubule - 4
water
- impermeable to water
- ADH can help water to be reabsorbed
distal convoluted tubule - 5
DCT controls pH balance by secreting H+ into filtrate / reabsorbs HCO3-
cortical collecting tubule - 1
SODIUM
- by epithelial sodium cells
- na/k-ATPase pump
- enhanced by aldosterone released from adrenal gland
cortical collecting tubule - 2
POTASSIUM
- principals cells secrete potassium
- enhanced by aldosterone + intercalated cells
cortical collecting tubule - 3
WATER
CCT is permeable to water
regulated by ADH
