Chapter 16 Study Questions (Pt. 2) Flashcards
what ion channels are primarily responsible for maintaining respiratory tract hydration? (5)
a. CFTR channels
b. Na+/K+/2Cl- symporters
c. Na+/K+ ATPases
d. K+ leak channels
e. ENaCs
what is the role of CF channels?
move Cl- into the lumen
how to open/close the CFTR gate?
open: ATP must bind to open the gate
close: gate closes when CFTR hydrolyzes ATP
how does Cl- move through a CF channel?
on a concentration gradient
on which membrane is this found: ENaC
apical
on which membrane is this found: CFTR
apical
on which membrane is this found: Cl-
apical
on which membrane is this found: aquaporin
apical and basolateral
on which membrane is this found: K+ leak channel
basolateral
on which membrane is this found: Na/K ATPase
basolateral
on which membrane is this found: sodium/potassium/2Cl
basolateral
how is excess Na+ removed from the cell?
Na+/K+ ATPases remove excess sodium
how is excess potassium removed from the cell?
K+ leaks out through potassium leak channels
how does water get into the airway lumen?
if no functional CF channels = Na enters lung epithelial cells = water pulled from airway lumen and mucus
what is the name of the process where water leaves the lumen?
absorption
what is the name of the process where water enters the lumen?
secretion
absorption: water enters or leaves lumen?
leaves
secretion: water enters or leaves lumen?
enters
which players are involved in absorption: (4)
ENaC brings sodium in from the lumen
Na/K ATPase kicks water out of cell to blood, brings potassium into the cell
aquaporins bring H2O from lumen to bloodstream
Cl- and H2O leave lumen for bloodstream
which players are involved in secretion:
NKCC1 move Cl- from blood, through the cell, into the lumen through CFTR
Cl- exits cell for lumen through Cl- channels
aquaporins bring H2O from blood to lumen
Cl- and H2O leave blood for lumen
