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

anterior triangle of the neck The anterior triangle is a region of the neck. Structure The triangle is inverted with its apex inferior to its base which is under the chin. Investing fascia covers the roof of the triangle while visceral fascia covers the floor. Anatomy M ...

Anatomy

Boundaries

It is bounded: * Posteriorly by (the anterior border of) the

sternocleidomastoid muscle The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and Anatomical terms of motion#Flexion and extension, flexion of the neck. ...

, * Anteroinferiorly by (the superior belly of) the

omohyoid muscle The omohyoid muscle is a muscle in the neck. It is one of the infrahyoid muscles. It consists of two bellies separated by an intermediate tendon. Its inferior belly is attached to the scapula; its superior belly is attached to the hyoid bone. Its ...

. * Superiorly by (the posterior belly of) the

digastric muscle The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a bilaterally paired suprahyoid muscle located under the jaw. Its posterior belly is attached to the mastoid notch of temporal bone, and its anterior belly ...

Roof

The roof is formed by: *

Integument In biology, an integument is the tissue surrounding an organism's body or an organ within, such as skin, a husk, Exoskeleton, shell, germ or Peel (fruit), rind. Etymology The term is derived from ''integumentum'', which is Latin for "a coverin ...

, *

Superficial fascia A fascia (; : fasciae or fascias; adjective fascial; ) is a generic term for macroscopic membranous bodily structures. Fasciae are classified as superficial, visceral or deep, and further designated according to their anatomical location. Th ...

, *

Platysma The platysma muscle or platysma is a :wikt:superficial, superficial muscle of the human neck that overlaps the sternocleidomastoid. It covers the anterior surface of the neck superficially. When it contracts, it produces a slight wrinkling of the ...

, *

Deep fascia Deep fascia (or investing fascia) is a fascia, a layer of dense connective tissue that can surround individual muscles and groups of muscles to separate into fascial compartments. This fibrous connective tissue interpenetrates and surrounds the m ...

Floor

The floor is formed by (parts of) the: *

Thyrohyoid membrane The thyrohyoid membrane (or hyothyroid membrane) is a broad, fibro-elastic sheet of the larynx. It connects the upper border of the thyroid cartilage to the hyoid bone. Structure The thyrohyoid membrane is attached below to the upper border of ...

, *

Hyoglossus The hyoglossus is a thin and quadrilateral extrinsic muscle of the tongue. It originates from the hyoid bone; it inserts onto the side of the tongue. It is innervated by the hypoglossal nerve (cranial nerve XII). It acts to depress and retract th ...

, * Constrictor pharyngis medius and constrictor pharyngis inferior muscles.

Arteries

Internal carotid artery The internal carotid artery is an artery in the neck which supplies the anterior cerebral artery, anterior and middle cerebral artery, middle cerebral circulation. In human anatomy, the internal and external carotid artery, external carotid ari ...

External carotid artery The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland. Structure Origin T ...

and some of its branches: **

Superior thyroid artery The superior thyroid artery arises from the external carotid artery just below the level of the greater cornu of the hyoid bone and ends in the thyroid gland. Structure From its origin under the anterior border of the sternocleidomastoid the super ...

, **

Ascending pharyngeal artery The ascending pharyngeal artery is an artery of the neck that supplies the pharynx. Its named branches are the inferior tympanic artery, pharyngeal artery, and posterior meningeal artery. inferior tympanic artery, and the meningeal branches (i ...

, **

Lingual artery The lingual artery arises from the external carotid artery between the superior thyroid artery and facial artery. It can be located easily in the tongue. Structure The lingual artery first branches off from the external carotid artery. It runs ...

, **

Facial artery The facial artery, formerly called the external maxillary artery, is a branch of the external carotid artery that supplies blood to superficial structures of the medial regions of the face. Structure The facial artery arises in the carotid t ...

, **

Occipital artery The occipital artery is a branch of the external carotid artery that provides arterial supply to the back of the scalp, sternocleidomastoid muscles, and deep muscles of the back and neck. Structure Origin The occipital artery arises from (the ...

Veins

internal jugular vein The internal jugular vein is a paired jugular vein that collects blood from the brain and the superficial parts of the face and neck. This vein runs in the carotid sheath with the common carotid artery and vagus nerve. It begins in the posteri ...

and its tributaries (correspondng to the branches of the corresponding artery): **

Superior thyroid vein The superior thyroid vein is the vena comitans of the superior thyroid artery. It is formed by the union of deep and superficial tributaries that correspond to the arterial branches of the superior thyroid artery. Its tributaries are the . The v ...

, **

Lingual veins The lingual veins are veins of the tongue with two distinct courses: one group drains into the lingual vein, while another group drains either into the lingual artery, (common) facial vein, or internal jugular vein. Clinical significance The ...

, **

Common facial vein The facial vein usually unites with the anterior branch of the retromandibular vein to form the common facial vein, which crosses the external carotid artery and enters the internal jugular vein at a variable point below the hyoid bone. From near ...

(draining into the

) ** Ascending pharyngeal vein, **

Occipital vein The occipital vein is a vein of the scalp. It originates from a plexus around the external occipital protuberance and superior nuchal line to the back part of the vertex of the skull. It usually drains into the internal jugular vein, but may als ...

(sometimes).

Nerves

Superficial to the

carotid sheath The carotid sheath is a condensation of the deep cervical fascia enveloping multiple vital neurovascular structures of the neck, including the common and internal carotid arteries, the internal jugular vein, the vagus nerve (CN X), and ansa c ...

lies the

hypoglossal nerve The hypoglossal nerve, also known as the twelfth cranial nerve, cranial nerve XII, or simply CN XII, is a cranial nerve that innervates all the extrinsic and intrinsic muscles of the tongue except for the palatoglossus, which is innervated b ...

, and

ansa cervicalis The ansa cervicalis (or ansa hypoglossi in older literature) is a loop formed by muscular branches of the cervical plexus formed by branches of cervical spinal nerves C1-C3. The ansa cervicalis has two roots - a superior root (formed by branch o ...

of the

cervical plexus The cervical plexus is a nerve plexus of the anterior rami of the first (i.e. upper-most) four cervical spinal nerves C1-C4. The cervical plexus provides motor innervation to some muscles of the neck, and the diaphragm; it provides sensory inne ...

. The

crosses both the internal and external carotids, curving around the origin of the

occipital artery The occipital artery is a branch of the external carotid artery that provides arterial supply to the back of the scalp, sternocleidomastoid muscles, and deep muscles of the back and neck. Structure Origin The occipital artery arises from (the ...

. Within the sheath, between the artery and vein, and behind both, is the

vagus nerve The vagus nerve, also known as the tenth cranial nerve (CN X), plays a crucial role in the autonomic nervous system, which is responsible for regulating involuntary functions within the human body. This nerve carries both sensory and motor fibe ...

; behind the sheath, the

sympathetic trunk The sympathetic trunk (sympathetic chain, gangliated cord) is a paired bundle of nerve fibers that run from the base of the skull to the coccyx. It is a major component of the sympathetic nervous system. Structure The sympathetic trunk lies just ...

. On the lateral side of the vessels, the

accessory nerve The accessory nerve, also known as the eleventh cranial nerve, cranial nerve XI, or simply CN XI, is a cranial nerve that supplies the sternocleidomastoid and trapezius muscles. It is classified as the eleventh of twelve pairs of cranial nerv ...

runs for a short distance before it pierces the

Sternocleidomastoideus The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and flexion of the neck. The sternocleidomastoid is innervated by the acces ...

; and on the medial side of the

external carotid The external carotid artery is the major artery of the head and upper neck. It arises from the common carotid artery. It terminates by splitting into the superficial temporal and maxillary artery within the parotid gland. Structure Origin Th ...

, just below the

hyoid bone The hyoid-bone (lingual-bone or tongue-bone) () is a horseshoe-shaped bone situated in the anterior midline of the neck between the chin and the thyroid-cartilage. At rest, it lies between the base of the mandible and the third cervical verte ...

, the internal branch of the

superior laryngeal nerve The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of the vagus nerve and additionally receives a sympathetic branch from the superior cervical ganglion. The superior laryngeal nerve ...

may be seen; and, still more inferiorly, the external branch of the same nerve.

Other

The superior portion of the larynx and inferior portion of the pharynx are also found in the anterior portion part of this space.

Additional images

File:Musculussternocleidomastodieus.png,

Sternocleidomastoid muscle The sternocleidomastoid muscle is one of the largest and most superficial cervical muscles. The primary actions of the muscle are rotation of the head to the opposite side and Anatomical terms of motion#Flexion and extension, flexion of the neck. ...

File:Gray386.png, Muscles of the neck. Anterior view. File:Gray512.svg, The triangles of the neck. (Anterior triangles to the left; posterior triangles to the right. Suprahyoid labeled at left.)

References

External links

* () * * {{Authority control Human head and neck Triangles of the neck

Anatomy

Boundaries

Roof

Floor

Contents

Arteries

Veins

Nerves

Other

See also

Additional images

References

External links