This site is targeted at medical and radiology professionals, contains user contributed content, and material that may be confusing to a lay audience. Use of this site implies acceptance of our Terms of Use.

Innervation of the heart

The heart has extrinsic and intrinsic innervation, which allows the heart to continue beating if the nerve supply to the heart is disrupted (e.g. in cardiac transplant).

The heart receives innervation from both the superficial and deep cardiac plexuses, which have both parasympathetic (from vagus nerve) and sympathetic inputs, which provide post-ganglionic fibres to the SA and AV nodes as well other parts of the cardiac conduction system. 

The cardiac conduction system is composed of:

  • sinoatrial (SA) node
  • internodal connections
  • atrioventricular (AV) node
  • bundle of His
  • right and left bundle branches
  • Purkinje fibres

Cardiac myocyte conduction spreads through the heart from myocyte-to-myocyte starting the SA (pacing) node then via the other parts of the cardiac conduction in turn. 

Each part of the cardiac conduction system has its own instrinsic pacemaker, which means that if a higher pacing centre (e.g. SA node) is damaged and stops functioning a lower pacing centre (e.g AV node) can take over. 


Related articles

Thoracic anatomy

Updating… Please wait.
Loadinganimation

Alert_accept

Error Unable to process the form. Check for errors and try again.

Alert_accept Thank you for updating your details.