"origin: branches of the 1st part of the subclavian artery"
"course: ascends posterior to the internal carotid artery in the transverse foramina of the cervical vertebrae"
"termination: combines with the contralateral vertebral artery to form the basilar artery"
"key relationships: posterior to the internal carotid artery; ascends anterior to the roots of the hypoglossal nerve (CN XII)"
"V1: segmental cervical, muscular and spinal branches"
"V2: anterior meningeal artery, muscular and spinal branches"
"V3: posterior meningeal artery"
"V4: anterior and posterior spinal arteries (ASA and PSA), perforating branches to medulla, posterior inferior cerebellar artery"
"V1: pre-foraminal segment"
"V1 (pre-foraminal)"
"V2 ascends through the transverse foramina of the cervical vertebrae, normally C6-C3. Here it is accompanied by the vertebral veins and the sympathetic nerves. It then turns superolaterally through the inverted L-shaped transverse foramen of C2."
"Numerous muscular branches are given off as the artery ascends, with relatively large ones passing posteriorly from V3 to supply the occipital triangle. They can anastomose with occipital branches of the ECA."
"V4: anterior and posterior spinal arteries (ASA and PSA), perforating branches to medulla, posterior inferior cerebellar artery"
"V4: anterior and posterior spinal arteries (ASA and PSA), perforating branches to medulla, posterior inferior cerebellar artery"
"ASA: upper cervical spinal cord, inferior medulla"
"PSA: dorsal spinal cord to conus medullaris"
"peak velocities (PV) can have a wide range amongst individuals, ranging from 20-60 cm/s ref"
Expected headings
"Segments"
"V1 (pre-foraminal)"
"V2 (foraminal)"
"V3 (atlantic, extradural or extraspinal)"
"V4 (intradural or intracranial)"
"key relationships: posterior to the internal carotid artery; ascends anterior to the roots of the hypoglossal nerve (CN XII)"
"Rarely, the right vertebral artery can have an aberrant origin distal to the left subclavian; see vertebral arteria lusoria."
"V3: atlantic, extradural or extraspinal segment"
"V3 (atlantic, extradural or extraspinal)"
"V3 ascends from the curved transverse foramen of C2 (axis) and sweeps laterally over the transverse process. It then curves superiorly passing immediately lateral to the lateral mass of C2 and the lateral C1/2 articulation before it passes through the transverse foramen of C1 (atlas). Exiting this foramen, V3 then once again courses posteriorly around the posterolateral border of the lateral mass of C1. Passing superomedially it grooves the upper surface of the posterior arch of C1 and will enter the spinal canal by piercing the posterior atlanto-occipital membrane, spinal dura and arachnoid to continue as V4. This tortuosity provides length and freedom for the vessel to stretch, straighten and bend during rotation of the head, which occurs at the atlanto-axial joints."
"V1: segmental cervical, muscular and spinal branches"
"V2: anterior meningeal artery, muscular and spinal branches"
"asymmetry due to vertebral arterial hypoplasia, absence or termination into PICA of one of the vertebral arteries is very common"