Cardiac plexus
Plexus cardiacus
NervousNervesWhole body
- What it is
- A web of autonomic nerves at the base of the heart - its superficial part below the aortic arch, its deep part between the arch and the tracheal bifurcation - fed by cardiac branches of both sympathetic trunks (cervical and upper thoracic ganglia) and both vagus nerves; it continues along the coronary arteries and into the lung roots.
- Function
- Sets heart rate and force: sympathetic fibres speed the SA node and strengthen contraction, vagal fibres slow the rate and AV conduction; it also carries cardiac pain fibres back to T1-T4.
- Size
- About 3-4 cm across; individual cardiac nerves 0.5-1 mm
- Clinical note
- Heart pain travels with the sympathetic fibres to T1-T4, so angina is felt in the chest, left arm and jaw (referred pain). A transplanted heart has no plexus connections, so its rate only rises slowly with circulating adrenaline.