The superior cardiac nerve arises by two or more branches from the

superior cervical ganglion The superior cervical ganglion (SCG) is part of the autonomic nervous system (ANS); more specifically, it is part of the sympathetic nervous system, a division of the ANS most commonly associated with the fight or flight response. The ANS is co ...

, and occasionally receives a filament from the trunk between the first and second cervical ganglia. It runs down the neck behind the

common carotid artery In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
Longus colli muscle; and crosses in front of the inferior thyroid artery, and recurrent nerve. The course of the nerves on the two sides then differs.

Right nerve

The right nerve, at the root of the neck, passes either in front of or behind the

subclavian artery In human anatomy, the subclavian arteries are paired major arteries of the upper thorax, below the clavicle. They receive blood from the aortic arch. The left subclavian artery supplies blood to the left arm and the right subclavian artery supplie ...

, and along the

brachiocephalic trunk The brachiocephalic artery (or brachiocephalic trunk or innominate artery) is an artery of the mediastinum that supplies blood to the right arm and the head and neck. It is the first branch of the aortic arch. Soon after it emerges, the brachioce ...

to the back of the arch of the

aorta The aorta ( ) is the main and largest artery in the human body, originating from the left ventricle of the heart and extending down to the abdomen, where it splits into two smaller arteries (the common iliac arteries). The aorta distributes ...

, where it joins the deep part of the cardiac plexus. It is connected with other branches of the sympathetic; about the middle of the neck it receives filaments from the

external laryngeal nerve The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of vagus nerve and in its course receives a branch from the superior cervical ganglion of the sympathetic nervous system. The superio ...

; lower down, one or two twigs from the

vagus The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right ...

; and as it enters the thorax it is joined by a filament from the

recurrent laryngeal nerve The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve (cranial nerve X) that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and le ...

. Filaments from the nerve communicate with the thyroid branches from the middle cervical ganglion.

Left nerve

The left nerve, in the thorax, runs in front of the left

common carotid artery In anatomy, the left and right common carotid arteries (carotids) (Entry "carotid"
in
aortic arch The aortic arch, arch of the aorta, or transverse aortic arch () is the part of the aorta between the ascending and descending aorta. The arch travels backward, so that it ultimately runs to the left of the trachea. Structure The aorta begins ...

, to the superficial part of the cardiac plexus.

References

External links

Sympathetic nervous system {{Portal bar, Anatomy