Cardiac Action Potential

Cardiac Action Potential

To the tune of “Dreaming” by Blondie

[Verse 1]
Phase 0 of the action potential
Is the depolarizing upstroke
Just calcium current in the SA node
Makes the upstroke much more slow
Than follower cells
Where sodium

[Chorus]
Ion currents
Drive action potentials
Ion currents
Drive action potentials

[Verse 2]
Phase 1 - rapid repolarization
Caused by sodium inactivation
In pacemaker cells, this does not occur
It’s only the ventricular
And atrial muscle
That has this ion current

[Bridge]
Phase 2 is the AP plateau
Occurs only in cardiac muscle
There is sustained calcium influx
Phase 3 - repolarization
Caused by the slow potassium
Channels which open in both cell types

[Verse 3]
Phase 4 - electric diastolic phase
The funny current it will activate
The pacemaker potential
In cells of the SA node
Not cardiac muscle
Where still the

[Chorus]
Ion currents
Drive action potentials
Ion currents
Drive action potentials