Nerves of the heart
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
The heart receives a sensitive, sympathetic and parasympathetic innervation. Sympathetic fibers that go in the composition of the cardiac nerves from the right and left sympathetic trunks, carry impulses that speed up the rhythm of the heart contractions and expand the lumen of the coronary arteries. Parasympathetic fibers (a component part of the cardiac branches of the vagus nerves) conduct impulses that slow the heart rate and narrow the lumen of the coronary arteries. Sensitive fibers from the receptors of the walls of the heart and its vessels go to the corresponding centers of the spinal cord and the brain in the composition of the heart nerves and heart branches.
The scheme of innervation of the heart (according to VP Vorobyov) can be represented as follows. The cardiac nerves and branches following to the heart form the extraorganic cardiac plexuses (superficial and deep) located near the arch of the aorta and pulmonary trunk. The intraorganic cardiac plexus is located in the walls of the heart and is distributed in all their layers.
The heart (sympathetic) nerves (upper, middle and lower cervical as well as thoracic) begin from the cervical and upper thoracic (II and V) nodes of the right and left sympathetic trunks (see "Autonomic nervous system"). Heart branches originate from the right and left vagus nerves (see "Wandering nerve").
The superficial out-of-cardiac plexus lies on the anterior surface of the pulmonary trunk and on the concave semi-circle of the aortic arch. A deep inorganic cardiac plexus is located behind the aortic arch (in front of the tracheal bifurcation). The upper left cervical cord plexus is joined by the upper left cervical cardiac nerve (from the left upper cervical sympathetic node) and the upper left heart branch (from the left vagus nerve). All the other named cardiac nerves and cardiac branches enter the deep out-of-cardiac plexus.
The branches of the extraorganic cardiac plexuses pass into a single intraorganic cardiac plexus. Depending on which of the layers of the heart wall it is located, this heart plexus is conventionally divided into closely related subepicardial, intramuscular and subendocardial plexuses. The intrahornal cardiac plexus contains nerve cells and their clusters that belong to the parasympathetic part of the autonomic nervous system and form small nerve cardiac nodules (ganglia cardiaca). Especially a lot of nerve cells in the subepicardial heart plexus. According to VP Vorobyev, the nerves that make up the subepicardial heart plexus have a regular arrangement (in the form of nodal fields) and innervate certain areas of the heart. Accordingly, six subepicardial cardiac plexuses are distinguished - three on the front side of the heart, three on the back:
- right front;
- left front. They are located under the epicardium of the anterior and lateral walls of the right and left ventricles on both sides of the arterial cone;
- the anterior plexus of the atria is localized in the anterior wall of the atria;
- the right posterior plexus descends from the back wall of the right atrium into the posterior wall of the right ventricle (fibers from the sinus-atrial node of the conduction system of the heart go from it);
- the left posterior plexus from the lateral wall of the left atrium continues downward into the posterior wall of the left ventricle;
- the posterior plexus of the left atrium (plexus of the galleric sinus) is located in the upper part of the posterior wall of the left atrium (between the mouths of the pulmonary veins).
[