ARDMS Cerebrovascular Flashcards
Where does the aortic arch originate?
The base of the left ventricle
Where does the innominate originate?
In the superior mediastinum (right side aortic arch)
Where does the left subclavian terminate?
The thoracic outlet
What are aortic arch variants?
Common origin innominate/LCCA, left vertebral off aorta, common origin both CCA’s
Where does the CCA bi-furcate into the ICA/ECA?
The superior aspect of the thyroid cartilage (C-4 level)
Where do the four to sixth cervical transverse processes of the RCCA lie?
Posteriorly
What does the carotid bifurcation contain?
Many receptor endings of the glossopharyngeal nerve which responds to blood pressure changes controlling intracranial pressure
How does the ICA lie in relation to the ECA?
Posterior and lateral
What does the ICA supply blood to?
Anterior portion of brain / eyes with branches to the forehead and nose
What are the four segments of the ICA?
Cervical, Petrous, Cavernous, and Cerebral
Which extra-cranial portion enters the skull at the carotid canal and has no major branches?
Cervical segment
Which segment ascends in the carotid canal curving to enter the cranial cavity and has no major branches?
Petrous segment
Which segment contains the “S” shaped carotid siphon?
Cavernous segment
What are the branches of the cavernous segment?
Cavernous, Meningeal, and Hypophyseal arteries
What is another name for the cerebral segment?
Supraclinioid
Which segment is the distal portion of the ICA?
Cerebral (supraclinoid)
What are the branches of the cerebral segment?
Ophthalmic, Middle Cerebral, Anterior Choroids, Anterior Cerebral, and Posterior Communicating Arteries
Does the ICA typically have extra-cranial branches?
No
What is the first branch of the ICA?
Ophthalmic Artery at the level of the carotid siphon
Where does the OA enter the orbit?
Optic foramen
What are the terminal branches of the OA?
Frontal, Nasal, and Supraorbital Arteries
What condition does the OA system provide?
Peri-orbital circulation (collateral circulation via anastomosis with ECA branches)
Where does the ICA terminate?
The Circle of Willis (into the anterior and middle cerebral arteries)
What does the ECA supply blood to?
Face, scalp and neck
What are the eight branches of the ECA?
Superior Thyroid, Ascending Pharyngeal, Lingual, Occipital, Facial, Posterior Auricle, Maxillary and Superficial Temporal Arteries
Which ECA branches are most vital to collateral circulation?
Those that communicate with the OA or vertebral artery
Where does the vertebral artery arise?
Upper and back portion of the proximal subclavian
Where does the vertebral artery enter the skull?
Foramen magnum
What are the vertebral arteries relation to the subclavian artery?
They are the first and largest branch
What does the vertebral artery supply blood to?
Posterior portion of brain
What is unique about the anatomy of the vertebral arteries?
Asymmetrical in size, left is usually larger than the right
Which four segments does the vertebral artery divide into?
Pre-vertebral, Cervical, Horizontal (Atlantic), and Intracranial segments
Where does the pre-vertebral artery enter?
Transverse foramen of C6
Where does the cervical segment span?
C6 through transverse foramen of C6
What does the cervical segment give rise to?
Multiple small branches which may anastomose ECA branches for collaterals (vertebral/carotid occlusion)
Where does the horizontal segment course?
Posteriorly within the vertebral sulcus, ascends anteromedially through the dura mater and loops between atlas/axis prior to entering skull
Where does the intracranial segment course?
From the dura mater through the foramen magnum and joins with the contralateral vertebral artery forming the basilar artery
What does the intracranial segment give rise to?
Multiple branches that supply the inferior surface of the cerebellum
What is another term for the vertebral and basilar arteries?
Vertebrobasilar circulation
