Morning Bouns Q - drforget

[ArchivalUser]

Q/ at phase zero or during phase zero of cardiac ventricular AP, what happens:

a Na influx
b Na influx and K efflux through ungated channels.
c Na influx and K efflux through ungated and gated channels.
d K efflux

[ArchivalUser]

A..Voltage-gated Na channels open

[ArchivalUser]

A. rapid NA influx

[ArchivalUser]

A-Na influx

[ArchivalUser]

CC.

[ArchivalUser]

a..

[ArchivalUser]

ok guys had to open my physio book, ungated K channels are always open, iK voltage K opens during depol. Then C,

Dont like excitable tissues

[ArchivalUser]

Phase 0 is the immediate depolarization that sends the voltage past the zero millivolt level, making it positive. This is due to the sudden increase in membrane permeability to sodium ions and decrease in potassium permeability

[ArchivalUser]

http://www.cvphysiology.com/Arrhythmias/A006.htm

[ArchivalUser]

Kaplan page 40...

iK1....Depolarization is the signal to close these channels,
Ungated K channel always open and unless **the memberane potential reaches the K equilibrium potential ~ -94 mV ....depolarization phase Starts at ~-94

http://www.youtube.com/watch?v=j9w1qylp4...r_embedded#!

please confirm the answer.Thank you