Unlike the action potential in skeletal muscle cells, the cardiac action potential is not initiated by nervous activity. Instead, it arises from a group of specialized cells known as pacemaker cells, that have …

This diagram illustrates the action potential profile of a nodal cell within the heart, with time plotted against membrane potential. From this diagram, several characteristics of a nodal cell can be noted.

The action potential includes a depolarization (activation) followed by a repolarization (recovery). The action potential occurs in all cardiac cells but its appearance varies depending on cell type.

The action potential originates in the sinus node cells, propagates through the whole heart via an active electrophysiological process called impulse conduction, and can be measured as the electrical …

May 12, 2025 · In this post, we’ll dive into the physiology of the cardiac action potential, focusing on how calcium influx is the key bridge between electrical excitation and mechanical contraction.

There are three general types of cardiac action potentials that are distinguished, in part, by the presence or absence of spontaneous pacemaker activity and by how rapidly they depolarize.

Cardiac action potential (AP) is defined as a small voltage change (approximately 0.1 V) that initiates the contraction of cardiac myocytes, enabling the orderly spread of electrical excitation and subsequent …

Nov 26, 2025 · Cardiac Action Potential Phases: Diagram of pacemaker vs non-pacemaker cell action potentials and their ions explained.

Jun 8, 2025 · This article looks at how action potentials spread in ventricular cells, their shape and modulation in disease states.

Discover how action potentials drive myocardial contraction, conduction, and ECG signals. Explore their role in the SA node and heart rate regulation.