High resolution

Module 7: Figure cardiac pacemaker

The major ionic channels and conductances that contribute to the cardiac pacemaker located in the sinoatrial node of the heart.

The membrane potential (Vm) undergoes two main changes: a slow depolarization (pacemaker depolarization) that occurs during diastole (the green-shaded region) that sets the stage for the periodic action potentials. There are three main components of the oscillator (boxes): the signalling system that regulates oscillator frequency, the membrane oscillator and the cytosolic Ca2+ oscillator. The channels shown in green generate the pacemaker potential as described in the text.