The cardiac plexus is a plexus

Plexus

A plexus is a part of nervous system. Plexus has a slightly different definition in vertebrates and in invertebrates.- In vertebrates :In vertebrates, a plexus is an area where nerves branch and rejoin. The electrical signals do not mix; rather, the fibres travel together with their electrical...

 of nerves situated at the base of the heart

Heart

The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...

 that innervates the heart.

Structure

The cardiac plexus is divided into a superficial part, which lies in the concavity of the aortic arch

Aortic arch

The arch of the aorta or the transverse aortic arch is the part of the aorta that begins at the level of the upper border of the second sternocostal articulation of the right side, and runs at first upward, backward, and to the left in front of the trachea; it is then directed backward on the left...

, and a deep part, between the aortic arch and the trachea

Vertebrate trachea

In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...

.

The two parts are, however, closely connected.

Superficial part

The superficial part of the cardiac plexus lies beneath the arch of the aorta, in front of the right pulmonary artery

Right pulmonary artery

The right pulmonary artery or right branch of the pulmonary artery, longer and larger than the left, runs horizontally to the right, behind the ascending aorta and superior vena cava and in front of the right bronchus, to the root of the right lung, where it divides into two branches...

.

It is formed by the superior cardiac branch of the left sympathetic trunk

Sympathetic trunk

The sympathetic trunks are a paired bundle of nerve fibers that run from the base of the skull to the coccyx.-Structure:...

 and the lower superior cervical cardiac branch of the left vagus nerve

Vagus nerve

The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...

.

A small ganglion, the cardiac ganglion of Wrisberg, is occasionally found connected with these nerves at their point of junction.

This ganglion, when present, is situated immediately beneath the arch of the aorta, on the right side of the ligamentum arteriosum

Ligamentum arteriosum

The ligamentum arteriosum is a small ligament attached to the superior surface of the pulmonary trunk and the inferior surface of the aortic arch...

.

The superficial part of the cardiac plexus gives branches

• (a) to the deep part of the plexus;
• (b) to the anterior coronary plexus; and
• (c) to the left anterior pulmonary plexus
  Pulmonary plexus
  The pulmonary plexus is an autonomic plexus formed from pulmonary branches of vagus nerve and the sympathetic trunk.It supplies the Bronchial tree and the visceral pleura....
  
  .

Deep part

The deep part of the cardiac plexus is situated in front of the bifurcation of the trachea

Vertebrate trachea

In tetrapod anatomy the trachea, or windpipe, is a tube that connects the pharynx or larynx to the lungs, allowing the passage of air. It is lined with pseudostratified ciliated columnar epithelium cells with goblet cells that produce mucus...

, above the point of division of the pulmonary artery, and behind the aortic arch.

It is formed by the cardiac nerves derived from the cervical ganglia of the sympathetic trunk, and the cardiac branches of the vagus and recurrent laryngeal nerve

Recurrent laryngeal nerve

The recurrent laryngeal nerve is a branch of the vagus nerve that supplies motor function and sensation to the larynx . It travels within the endoneurium...

s.

The only cardiac nerves which do not enter into the formation of the deep part of the cardiac plexus are the superior cardiac nerve of the left sympathetic trunk, and the lower of the two superior cervical cardiac branches from the left vagus nerve, which pass to the superficial part of the plexus.

Right half

The branches from the right half of the deep part of the cardiac plexus pass, some in front of, and others behind, the right pulmonary artery; the former, the more numerous, transmit a few filaments to the anterior pulmonary plexus, and are then continued onward to form part of the anterior coronary plexus; those behind the pulmonary artery distribute a few filaments to the right atrium, and are then continued onward to form part of the posterior coronary plexus.

Left half

The left half of the deep part of the plexus is connected with the superficial part of the cardiac plexus, and gives filaments to the left atrium, and to the anterior pulmonary plexus, and is then continued to form the greater part of the posterior coronary plexus.

External links

(superficial) (deep)