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 posterior aspect of) the
external carotid artery (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 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,
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, and
digastricus, 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 with the
sternocleidomastoideus, 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 with the
posterior auricular and
superficial temporal arteries.
Distribution
# Muscular branches: supply the
digastric,
stylohyoid,
splenius, 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
sternocleidomastoid, 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
#
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