Anatomy of the Vertebral Artery
This quiz is the first of a series concerning the vertebral artery. Of all the problems faced by the orthopedic manual therapist, the vertebral artery is perhaps the most significant for the degree of damage that it can do to the patient when injured.
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The artery typically originates from the subclavian. What is the most common variation in its origin?
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Name the four parts of the artery and each part's usual distal and proximal boundaries.
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What are the structures that form the transverse tunnel and what is unusual about the artery in this part of its course.
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List the branches of the vertebral artery and the structures they vascularize.
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List the branches of the basilar artery and the structures they vascularize.
1. The most common variation in the origin of the vertebral artery: The left artery originating from the aorta. This occurs about 4% of the time and is usually associated with a higher than normal entry into the transverse tunnel (C4 or 5).
2. The parts are:
Osteal - from its origin to the transverse tunnel (normally C6 transverse foramen)
Transverse - from its entry in the transverse tunnel cranially through the tunnel to its entrance at C2 transverse foramen
Suboccipital - from the C2 transverse foramen into the foramen magnum
Intracranial - from the foramen magnum to the lower border of the pons.
3. The structures that form the transverse tunnel are the transverse foramina, the zygopophyseal joints, the uncovertebral joints, the lateral aspects of the disc and vertebral bodies, the scalenes and the longus colli.
4. Vertebral artery branches and vascularization:
Radicular - dural sleeve, spinal nerve, nerve roots
Osseomuscular - axis and atlas bones, suboccipital muscles, occipital bone
Meningeal - occipital meninges Anterior spinal artery - anterior portion of the spinal cord
Posterior spinal artery (variant normally arises from the PICA) - posterior portion of the spinal cord
Medullary - medulla
Posterior inferior cerebellar artery - cerebellum and medulla
Basilar - pons, midbrainis the non-volitional movement that occurs as part (conjoined) of another main movement and is produced by the shape of the joint surfaces and ligaments.
5. Basilar artery branches and vascularization:
Pontine branches - pons
Anterior inferior cerebellar artery - pons and cerebellum
Superior cerebellar artery - pons, midbrain and cerebellum
Internal auditory (labyrinthine) - membranous labyrinth and 8th cranial nerve
Superior cerebral - thalamus (central), temporal lobe (temporal branch of the cortical) and occipital lobe (calcerine branch of the cortical)
References:
George, B. Laurian, C. The vertebral artery: pathology and surgery. N.Y. Springer-Verlag Wien 1987
Williams, PL. Warwick, R. editors, Gray's Anatomy 36th edition. Edinburgh, Churchill Livingston 1980
Padget, DH. The development of cranial arteries in the human embyro. Contrib Embryiol 32:205-262 1948
Wilkinson, IMS. The vertebral artery: extra and intracranial structure. Arch Neurol 27:393-396 1972
Franke, JP, etal. The vertebral arteries. Anatomica Clinica 2:229-242 1981
Disclaimer:
The assessment and treatment techniques depicted or described in this site are not intended to replace formal instruction in orthopedic manual or any other type of physical therapy. They are intended to review, augment and facilitate the knowledge and skills previously gained on manual therapy or other course and to stimulate the untrained or trainee physical therapist to increase the bounds of his or her knowledge and skill base.
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