- Vertebral artery
Name = Vertebral artery
Latin = arteria vertebralis
GraySubject = 148
GrayPage = 578
Caption = Arteries of the neck. The vertebral arteries arise from the subclavian arteries and join to form the
basilar artery. It is ponted out, centermost of the three vertical arteries.
Caption2 = The three major arteries of the cerebellum: the SCA, AICA, and PICA. (Vertebrals labeled at bottom.)
BranchFrom = subclavian arteries
BranchTo = Meningeal branches
MeshName = Subclavian+Artery
MeshNumber = A07.231.114.839
DorlandsPre = a_61
DorlandsSuf = 12156505
The vertebral arteries are branches of the subclavian arteries.
The two vertebral arteries and the
basilar arteryare sometimes together called the vertebrobasilar system, which supplies blood to the posterior part of circle of Willisand anastomoses with blood supplied to the anterior part of the circle of Willis from the carotid arteries.
They arise, one on each side of the body, then enter deep to the transverse process of the level of the 6th
It then proceeds superiorly, in the
transverse foramen(foramen transversarium) of each cervical vertebrauntil C1.
This path is largely parallel to, but distinct from, the route of the
carotid arteryascending through the neck.
At the C1 level the vertebral arteries travel across the posterior arch of the atlas before entering the
Inside the skull, the two vertebral arteries join up to form the
basilar arteryat the base of the medulla oblongata.
basilar arteryis the main blood supply to the brainstemand connects to the Circle of Willisto potentially supply the rest of the brain if there is compromise to one of the carotids.
At each cervical level, the vertebral artery sends branches to the surrounding musculature via
anterior spinal arteries.
Division into four parts
The vertebral artery may be divided into four parts:
The first part runs upward and backward between the
Longus colliand the Scalenus anterior.
In front of it are the
internal jugularand vertebral veins, and it is crossed by the inferior thyroid artery; the left vertebral is crossed by the thoracic ductalso.
Behind it are the transverse process of the seventh
cervical vertebra, the sympathetic trunkand its inferior cervical ganglion.
The second part runs upward through the
foraminain the transverse processesof the upper six cervical vertebræ, and is surrounded by branches from the inferior cervical sympathetic ganglion and by a plexus of veins which unite to form the vertebral vein at the lower part of the neck.
It is situated in front of the trunks of the cervical nerves, and pursues an almost vertical course as far as the
transverse process of the atlas, above which it runs upward and lateralward to the foramen in the transverse process of the atlas.
The third part issues from the latter foramen on the medial side of the
Rectus capitis lateralis, and curves backward behind the superior articular process of the atlas, the anterior ramus of the first cervical nerve being on its medial side; it then lies in the groove on the upper surface of the posterior arch of the atlas, and enters the vertebral canal by passing beneath the posterior atlantoöccipital membrane.
This part of the artery is covered by the
Semispinalis capitisand is contained in the suboccipital triangle—a triangular space bounded by the Rectus capitis posterior major, the Obliquus superior, and the Obliquus inferior.
The first cervical or
suboccipital nervelies between the artery and the posterior archof the atlas.
The fourth part pierces the
dura materand inclines medialward to the front of the medulla oblongata; it is placed between the hypoglossal nerveand the anterior root of the first cervical nerve and beneath the first digitation of the ligamentum denticulatum.
At the lower border of the
ponsit unites with the vessel of the opposite side to form the basilar artery.
The left vertebral artery is usually larger and carries more blood. [cite journal |author= Albayrak, Ramazan|title=Doppler sonography evaluation of flow velocity and volume of the extracranial internal carotid and vertebral arteries in healthy adults |journal=J Clin Ultrasound |volume=35 |issue=1 |pages=27–33 |year=2007 |pmid=17149761|doi=10.1002/jcu.20301]
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