Carotid triangle

The carotid triangle (or superior carotid triangle) is a portion of the anterior triangle of the neck.

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Coverings and boundaries

It is bounded:

• behind by the Sternocleidomastoideus;
• below, by the superior belly of the Omohyoideus
• above, by the Stylohyoideus and the posterior belly of the Digastricus.

It is covered by the integument, superficial fascia, Platysma and deep fascia; ramifying in which are branches of the facial and cutaneous cervical nerves.

Its floor is formed by parts of the Thyrohyoideus, Hyoglossus, and the Constrictores pharyngis medius and inferior.

Arteries

This space when dissected is seen to contain the upper part of the common carotid artery, which bifurcates opposite the upper border of the thyroid cartilage into the external and internal carotid. These vessels are somewhat concealed from view by the anterior margin of the Sternocleidomastoideus, which overlaps them.

The external and internal carotids lie side by side, the external being the more anterior of the two.

The following branches of the external carotid are also met with in this space:

• the superior thyroid artery, running forward and downward;
• the lingual artery, directly forward;
• the facial artery , forward and upward;
• the occipital artery , backward;
• the ascending pharyngeal artery, directly upward on the medial side of the internal carotid.

Veins

The veins met with are:

• the internal jugular, which lies on the lateral side of the common and internal carotid arteries;
• and veins corresponding to the above-mentioned branches of the external carotid—viz.,
  • the superior thyroid,
  • the lingual,
  • common facial,
  • ascending pharyngeal,
  • and sometimes the occipital

...all of which end in the internal jugular.

Nerves

The nerves in this space are the following.

In front of the sheath of the common carotid is the ramus descendens hypoglossi.

The hypoglossal nerve crosses both the internal and external carotids above, curving around the origin of the occipital artery.

Within the sheath, between the artery and vein, and behind both, is the vagus nerve; behind the sheath, the sympathetic trunk.

On the lateral side of the vessels, the accessory nerve runs for a short distance before it pierces the Sternocleidomastoideus; and on the medial side of the external carotid, just below the hyoid bone, may be seen the internal branch of the superior laryngeal nerve; and, still more inferiorly, the external branch of the same nerve.

Other contents

The upper portion of the larynx and lower portion of the pharynx are also found in the front part of this space.

See also

• Anterior triangle of the neck

Additional images

This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.