Tubular Re-absorption

Question 1

where sodium and calcium reabsorbed

Answer 1

mostly proximal tubule, some loop of henle, little distal tubule, itty bitty collecting duct

Ca only filtered if not bound to plasma protein

Question 2

where phosphate, glucose, amino acids reabsorbed at

Answer 2

proximal tubule only
-glucose and AA are 100%, phos only 80%

Question 3

oligopeptide reabsorption

Answer 3

in proximal tubule only but uses endocytosis and transcytosis

Question 4

loop of henle absorption mechanism

Answer 4

for sodium via NKCC transporter
-loop diuretics target (furosemide, bumetanide)

Question 5

Bartter syndrome

Answer 5

mutation in NKCC so NaCl and K reabsorption decreased = hypokalemia and dec ECF vol

Question 6

distal tubule absorption mechanism

Answer 6

for NaCl via NCC
-thiazide like diuretics target

Question 7

Gitelman syndrome

Answer 7

mutation of NCC that inactivates so fluid and electrolyes disturbances

Question 8

collecting duct absorption mechanism

Answer 8

for NaCl via ENaC
-potassium sparing diuretics target

Question 9

Liddle syndrome

Answer 9

mutation in ENaC so inc # of Na channels = inc ECF vol and BP (hypertension)

Question 10

glucose transport

Answer 10

filtration and transport happen in parallel until splay point then transport plateus
-excretion starts when threshold reached

Question 11

major causes of glucose in urine

Answer 11

1. plasma glucose exceeds transport for reabsorption like diabetes
2. mutations in glucose transporters

Question 12

favoring reabsorption

Answer 12

oncotic capillary P
hydrostatic interstitial P

Question 13

opposing reabsorption

Answer 13

hydrostatic capillary P
oncotic interstitial P

Question 14

if colloid osmotic P dec

Answer 14

from injury that inc permeability to proteins so solutes are being excreted
-net reabsorption pressure is not enough for a gradient = edema and red plasma vol