Cerbrovascular Anatomy Flashcards
is the internal or external larger? which one feeds the brain?
where do the vertebrals pass through?
Aortic Arch
Brachiocephalic (Innominate) :
Rt CCA:ICA, ECA
Rt Subclavian: Vertebral
Lt CCA off Arch: ICA, ECA
Lt Subclavian off arch: Vertebral
*internal is bigger than external and feeds brain and inside of skull external has branches coming off if and feeds superficial (head, neck…)
vetebrals go through transverse processes of the c-spine
know the anatomy
what are some common arch variations?
carotids are ____ to the thyroid
_______attaches clavicle to sternum. muscle drags across neck. pokes out when you clench your fist. you can image through it
Thyroid is:
___ to CCA and in the
_____ part of the neck
Trachea – midline, shadow due to ___
Internal jugular vein
____ to CCA and normally ____
Sternocleidomastoid muscle
___ to CCA and IJV
Window from ____ approach
lateral
sternocleidomastoic muscle
Medial, mid-inferior
air
Lateral and collapsible
Lateral, lateral
label
label
Carotid Bulb
ICA: Carotid siphon (canal) and Ophthalmic (Frontal, Supraorbital, Nasal (supratrochlear)
MCA – lateral cerebrum
ACA – anterior cerebrum
Communicating: Anterior comm – connect rt and lt ACA and Posterior comm – connect PCAs to terminal ICAs
first branch- if not enough flow through carotid causes vision problems
goes through ridges
NO neck branches! going to head/brain goes straight up through the middle of the skull.
branches of the opthalmic distal branches of ICA
label
label
Right and left cerebrum (excluding occipital lobe) connected by _____
cerebellum and brain stem fed by __________ .
Anterior circulation and Posterior circulation connected by ________________.
Posterior right and left circulation connected by ________.
Ant Communicating
Basilar
posterior communicating
posterior cerebral artery
*designed so if something goes down in one vessel, blood will still feed the brain
label
label
All areas of the brain fed by the ____ and their branches. This includes ______ hemispheres (except occipital lobe).
Symptoms occur on _______ of the vascular accident.
CCA, cerebral
opposite side *the dominant hemisphere is opposite of “handedness” of person.
anterior communicators connect _____
anterior basilar connects ___________
circulation posterior communicators connect _________
right and left
rt and lt posterior
anterior and posterior circulation
in posterior circulation, all areas of the brain fed by vertebrals, basilar and PCAs. This is the ____ and _____.
cerebellum, brainstem and occipital lobe
what are possible anastomoses for th eobstructed ICA?
increased flow and increased VOL of flow in the rt side of the brain s it’s supplying blood to the entire brain
image below: Obstructed ICA
Vertebrobasilar via Post Comm and PCA
increased flow in vertebral
Contralateral ICA via Ant Communicating and ACA
causes: Increased flow contralateral ICA, Flow in Ant comm, Reversed flow A1 of ispilateral ACA
Obstructed ICA
Distal ECA to Distal ICA anastomosis:
Superficial temp to supraorbital/frontal
Facial/angular to nasal
Maxillary/Middle meningeal to ophthalmic
Maxillary/Infraorbital to nasal
“internalization of ECA”
Potential collateral pathways with ICA occlusion
Bilateral Obstructed ICA
Vertebrobasilar via post comm and PCAs – increased flow in vert.
vertebrals feeding basilar via post communicators
Obstructed subclavian proximal to vertebral branch is aka as ______. It is most commonly on the ___ side.
Subclavian steal syndrome – increased flow in contralateral vert, across basilar, reversed ipsilateral vert to brachial.
Most commonly on lt.
feeding left arm via rt vetebral in doppler it will be going the wrong way pressure will be lower in left arm
Obstructed CCA
Reversed flow in ECA, normal direction in ICA. Blood coming from contralateral ECA, across branches in the face (usually nose or forehead) to ipsilateral ECA.
obstructed CCA
Reversed flow in ECA, normal direction in ICA. Blood coming from contralateral ECA, across branches in the face (usually nose or forehead) to ipsilateral ECA.
what side can brachiocephalic be obstructed on?
what hapens simultaneously?
what happens with the flow then?
only on the RT
Carotid steal and subclavian steal simultaneously.
Carotid steal – flow reversed in ipsilateral ECA, u-turn at bulb and correct direction in ICA. Blood via ECA to ECA collaterals over nose and forehead.
this is an example of ____.
what is happening to the flow?
Obstructed brachiocephalic
Carotid steal and subclavian steal simultaneously.
Subclavian steal syndrome – increased flow in contralateral vert, across basilar, reversed ipsilateral vert to brachial.
Only happens on RT.
what anastomesis happens w/ obstructed vertebral?
what happens to the ECA?
between occipital branch of ECA and vertebral.
internatlization
*These could also anastomose with cervical branches of SC, so ECA would be feeding arm.
anatomy summary
Rt BC
Lt CCA
Lt SC
CCA : ICA (Carotid Siphon), ECA
Subclavian: Vertebral, Axillary (arm)
CCA:
ICA (Ophthalmic, Circle of Willis)
ECA (Cervical – ST, Facial)
Subclavian:
Vertebral
Axillary (arm)
___ resistance flow required for the brain via:
___ resistance flow in vessels feeding soft tissue and muscle VIA:
Low, ICA, Vertebrals and Intracranial arteries (top)
Higher, ECA, Subclavian (bottom)
what vessel is represented in each waveform?
ICA, Vertebral Artery, low resistance
what waveforms are rep here?
ECA, Subclavian, higher resistance feeding soft tissue and muscle.
name the vessels
ICA - low resistance to brain, more flow
ECA - systolic spike, some diastolic flow
Vertebral - low resistance
