Which of these conditions occur in the cardiac muscle cell during the plateau phase?
A) voltage-gated Ca2+ ion channels are open
B) voltage-gated K+ ion channels are open
C) voltage-gated Na+ ion channels are closed
D) all of these
i think its a. can u pls give d right answer?
a
Phase 0: Rapid depolarization
- increased Na+ and decreased K+
conductances
Phase 1: Initial repolarization
- decreased Na+ and increased K+
conductances*
Phase 2: Plateau phase
- increased Ca++ conductance
Phase 3: Repolarization
- increased K+ and decreased Ca++ conductances
Phase 4: Resting potential
- increased K+ and decreased Na+ and decreased Ca++ conductances
but plateua phase also has K+ conductance along with Ca++ conduntance thats why it is plateau
bedidee
any channel will not stop completely at anytime.....but some will be more active that matters....yes K+ will be oosing out as well but platue phase is due to Ca++ and repolarisation is due to k+
u r right ashlin.... plateau phase is due to voltage gated Ca++ channels, K+ does go out ut due to ungated K+ channels not due to voltage gated K+ channles,,,,
bedidee: how about the Na voltage channels arent they closed during platue?!