last updated 24-06-2024

Innervation of the heart

Innervation of the heart

The sinoatrial node (SA node) generates rhythmic pulses in the right atrium. The pacemaker cells in the SA node spontaneously generate 80–100 action potentials per minute. The pulse is rapidly conducted through the atria. The next station for conductance is the atrioventricular node (AV node), which is the only electrical connection between atrium and ventricle. The AV node controls the passage of impulses towards the bundle of His in the septum between the two ventricles.


The pulse is then further distributed over the ventricles via the Purkinje fibers. The heart itself is innervated by autonomic nerves originating in the cardiovascular centres of the medulla oblongata. Parasympathetic innervation goes via the vagus nerve; sympathetic nerves have several connection points (spinal cord and sympathetic ganglion).


The serous membrane covering the outer surface of the heart is the


The autonomic centers for cardiac function are located in the


What is NOT true about cardiac contraction?


The effect of noradrenaline on the heart does NOT include:


What is NOT true about the heart?