The superior cardiac nerve arises by two or more branches from the superior cervical ganglion, 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 The longus colli muscle (Latin for ''long muscle of the neck'') is a muscle of the human body. The longus colli is situated on the anterior surface of the vertebral column, between the atlas and the third thoracic vertebra. It is broad in the m ...

; and crosses in front of the

inferior thyroid artery The inferior thyroid artery is an artery in the neck. It arises from the thyrocervical trunk and passes upward, in front of the vertebral artery and longus colli muscle. It then turns medially behind the carotid sheath and its contents, and als ...

, and

recurrent 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 ...

. 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, 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 brachi ...

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 o ...

, where it joins the deep part of the

cardiac plexus The cardiac plexus is a plexus of nerves situated at the base of the heart that innervates the heart. Structure The cardiac plexus is divided into a superficial part, which lies in the concavity of the aortic arch, and a deep part, between the ao ...

. It is connected with other branches of the sympathetic; about the middle of the neck it receives filaments from the external laryngeal nerve; 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 v ...

; 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 ...

. Filaments from the nerve communicate with the thyroid branches from the

middle cervical ganglion The middle cervical ganglion is the smallest of the three cervical ganglia, and is occasionally absent. It is placed opposite the sixth cervical vertebra, usually in front of, or close to, the inferior thyroid artery. It sends gray rami communican ...

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

References

External links

Sympathetic nervous system {{Portal bar, Anatomy