The occipital artery is a branch of the

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 ...

that provides arterial supply to the back of the scalp,

sternocleidomastoid 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 ...

muscles, and deep muscles of the back and neck.

Structure

Origin

The occipital artery arises from (the posterior aspect of) the

(some 2 cm distal to the origin of the external carotid artery).

Course and relations

At its origin, the hypoglossal nerve (CN XII) crosses artery superficially as the nerve passes posteroanteriorly. The artery passes superoposteriorly deep to the posterior belly of the digastricus muscle. It crosses the

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 ...

and

vein Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and feta ...

, the vagus nerve (CN X), accessory nerve (CN XI), and hypoglossal nerve (CN XII). It next ascends to the interval between the transverse process of the

atlas An atlas is a collection of maps; it is typically a bundle of world map, maps of Earth or of a continent or region of Earth. Advances in astronomy have also resulted in atlases of the celestial sphere or of other planets. Atlases have traditio ...

and the

mastoid process The mastoid part of the temporal bone is the posterior (back) part of the temporal bone, one of the bones of the skull. Its rough surface gives attachment to various muscles (via tendons) and it has openings for blood vessels. From its borders, t ...

of the

temporal bone The temporal bone is a paired bone situated at the sides and base of the skull, lateral to the temporal lobe of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples where four of the cranial bone ...

, and passes horizontally backward, grooving the surface of the latter bone, being covered by 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 ...

splenius capitis The splenius capitis () () is a broad, straplike muscle in the back of the neck. It pulls on the base of the skull from the vertebrae cervical vertebra, in the neck and upper Thoracic vertebrae, thorax. It is involved in movements such as shaking ...

longissimus capitis The longissimus () is the muscle lateral to the semispinalis muscles. It is the longest subdivision of the erector spinae muscles that extends forward into the transverse processes of the posterior cervical vertebrae. Structure Longissimus tho ...

, and

digastricus 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 ...

, and resting upon the rectus capitis lateralis, the obliquus superior, and semispinalis capitis. It then changes its course and runs vertically upward, pierces the fascia connecting the cranial attachment of the

trapezius The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the human spine, spine and laterally to the spine of the scapula. It moves the scapula and ...

with the

, and ascends in a tortuous course in the superficial fascia of the scalp, where it divides into numerous branches, which reach as high as the vertex of the skull and

anastomose An anastomosis (, : anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal (su ...

with the posterior auricular and superficial temporal arteries.

Distribution

# Muscular branches: supply the

digastric 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 ...

, stylohyoid,

splenius The splenius muscles are: *Splenius capitis muscle *Splenius cervicis muscle Their origins are in the upper thoracic and lower cervical spinous process Each vertebra (: vertebrae) is an irregular bone with a complex structure composed of bo ...

, and longus capitis muscles. # Sternocleidomastoid branch: This branch divides into upper and lower branches in the carotid triangle. The upper branch accompanies the accessory nerve to the

, and the lower branch arises near the origin of the occipital artery before entering the sternocleidomastoid muscle. Occasionally, this branch arises directly from the external carotid artery. # Auricular branch: supplies the back of the ear. In many specimens, this branch gives rise to the mastoid branch, which supplies the dura mater, diploe, and mastoid air cells. In other specimens, the mastoid artery is a branch of the occipital artery, rather than the auricular branch. # Meningeal branch: supplies the dura mater in the

posterior cranial fossa The posterior cranial fossa is the part of the cranial cavity located between the foramen magnum, and tentorium cerebelli. It is formed by the sphenoid bones, temporal bones, and occipital bone. It lodges the cerebellum, and parts of the brai ...

# Descending branches: This is the largest branch. It descends on the posterior aspect of the neck, and divides into a superficial and deep portion. The superficial portion supplies the

trapezius muscle The trapezius is a large paired trapezoid-shaped surface muscle that extends longitudinally from the occipital bone to the lower thoracic vertebrae of the human spine, spine and laterally to the spine of the scapula. It moves the scapula and ...

and anastomoses with the ascending branch of the transverse cervical. The deep portion anastomoses with the

vertebral artery The vertebral arteries are major artery, arteries of the neck. Typically, the vertebral arteries originate from the subclavian arteries. Each vessel courses superiorly along each side of the neck, merging within the skull to form the single, m ...

and with the a. profunda cervicalis, a branch of the costocervical trunk. Thus, branches of the occipital artery participate in anastomosis between the external carotid and the subclavian artery, thereby providing

collateral circulation Collateral circulation is the alternate Circulatory system, circulation around a blocked blood vessel, artery or vein via another path, such as nearby minor vessels. It may occur via preexisting vascular redundancy (analogous to redundancy (engi ...

. Its terminal portion is accompanied by the greater occipital nerve.

Additional images

Image:Gray513.png, The internal carotid and vertebral arteries. Right side. Image:Gray790.png, The nerves of the scalp, face, and side of neck. Image:Gray1210.png, Side of neck, showing chief surface markings. Image:Lateral head anatomy detail.png, Lateral head anatomy detail

References

External links

* ()
Diagram at stchas.edu
* http://www.dartmouth.edu/~humananatomy/figures/chapter_47/47-2.HTM {{Authority control Arteries of the head and neck Otorhinolaryngology Human head and neck Cardiovascular system