The occipital artery arises from the external carotid artery opposite the facial artery. Its path is below the posterior belly of

digastric The digastric muscle (also digastricus) (named ''digastric'' as it has two 'bellies') is a small muscle located under the jaw. The term "digastric muscle" refers to this specific muscle. However, other muscles that have two separate muscle belli ...

to the

occipital The occipital bone () is a cranial dermal bone and the main bone of the occiput (back and lower part of the skull). It is trapezoidal in shape and curved on itself like a shallow dish. The occipital bone overlies the occipital lobes of the cereb ...

region. This artery supplies blood to the back of the scalp and sternocleidomastoid muscles, and deep muscles in the back and neck.

Structure

At its origin, it is covered by the posterior belly of the digastricus and the

stylohyoideus The stylohyoid muscle is a Gracility, slender muscle, lying anterior and Anatomical terms of location#Superior and inferior, superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's inn ...

, and 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 by ...

winds around it from behind forward; higher up, it crosses the internal carotid artery, the

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 poste ...

, and 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

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 ...

s. 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 maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geograp ...

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, ...

of the

temporal bone The temporal bones are situated at the sides and base of the skull, and lateral to the temporal lobes of the cerebral cortex. The temporal bones are overlaid by the sides of the head known as the temples, and house the structures of the ears. ...

, 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 access ...

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 in the neck and upper thorax. It is involved in movements such as shaking the head. Structure It arises from th ...

longissimus capitis The longissimus ( la, the longest one) 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. Structu ...

, and digastricus, and resting upon the

rectus capitis lateralis The rectus capitis lateralis, a short, flat muscle, arises from the upper surface of the transverse process of the atlas, and is inserted into the under surface of the jugular process of the occipital bone. Additional images File:Rectus capitis ...

, the

obliquus superior The superior oblique muscle, or obliquus oculi superior, is a fusiform muscle originating in the upper, medial side of the orbit (i.e. from beside the nose) which abducts, depresses and internally rotates the eye. It is the only extraocular mus ...

, and

semispinalis capitis The semispinalis muscles are a group of three muscles belonging to the transversospinales. These are the semispinalis capitis, the semispinalis cervicis and the semispinalis thoracis. The semispinalis capitis (''complexus'') is situated at the ...

. 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 spine and laterally to the spine of the scapula. It moves the scapula and supports th ...

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 (, plural 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 ...

with the posterior auricular and

superficial temporal In human anatomy, the superficial temporal artery is a major artery of the head. It arises from the external carotid artery when it splits into the superficial temporal artery and maxillary artery. Its pulse can be felt above the zygomatic arch ...

arteries.

Function

# Muscular branches: supply the

stylohyoid The stylohyoid muscle is a slender muscle, lying anterior and superior of the posterior belly of the digastric muscle. It is one of the suprahyoid muscles. It shares this muscle's innervation by the facial nerve, and functions to draw the hyoid ...

splenius The splenius muscles are: *Splenius capitis muscle *Splenius cervicis muscle Their origins are in the upper thoracic and lower cervical spinous process The spinal column, a defining synapomorphy shared by nearly all vertebrates, Hagfish are ...

, and

longus capitis The longus capitis muscle (Latin for ''long muscle of the head'', alternatively rectus capitis anticus major), is broad and thick above, narrow below, and arises by four tendinous slips, from the anterior tubercles of the transverse processes of th ...

muscles. # Sternocleidomastoid branch: This branch divides into upper and lower branches in the

carotid triangle The carotid triangle (or superior carotid triangle) is a portion of the anterior triangle of the neck. Coverings and boundaries It is bounded: * Posteriorly by the anterior border of the Sternocleidomastoid; * Anteroinferiorly, by the superior bel ...

. 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 In neuroanatomy, dura mater is a thick membrane made of dense irregular connective tissue that surrounds the brain and spinal cord. It is the outermost of the three layers of membrane called the meninges that protect the central nervous system. ...

, 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 part of the cranial cavity, located between the foramen magnum and tentorium cerebelli. It contains the brainstem and cerebellum. This is the most inferior of the fossae. It houses the cerebellum, medulla and pons. ...

# 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 spine and laterally to the spine of the scapula. It moves the scapula and supports the ...

and anastomoses with the ascending branch of the transverse cervical. The deep portion anastomoses with the vertebral artery 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. Its terminal portion is accompanied by the

greater occipital nerve The greater occipital nerve is a nerve of the head. It is a spinal nerve, specifically the medial branch of the dorsal primary ramus of cervical spinal nerve 2. It arises from between the first and second cervical vertebrae, ascends, and then p ...

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