Electrical activity of the heart Flashcards
1
Q
What does the cardiac muscle’s long refractory period mean?
A
It cannot contract until it is relaxed
Makes sure there is no tetanus
2
Q
What creates the plateau effect in the non-pacemaker cells?
A
The influx of Calcium
The loss of membrane permeability for potassium
3
Q
Which type of channels nudge the pacemaker cells towards threshold?
A
T-type (tiny) calcium channels
4
Q
What is seen as the “pacemaker” of the cell?
A
The SA node
5
Q
What happens to the signal once it reaches the AV node?
A
The signal is delayed by the AV node
6
Q
Why is the electrical signal delayed at the AV node?
A
It allows the atria to expel their blood into the ventricles
