Brain Blood Supply

arteries in the brain

Circle of Willis

◦ Internal carotd arteries

◦ Anterior cerebral arteries

◦ Middle cerebral arteries

◦ Posterior cerebral arteries

◦ Basilar artery

◦ Vertebral arteries

basilar artery

to the brain stem, cerebella and occipital lobes

•

which control the autonomic nervous system

(unconscious functons like breathing, heart

rate, etc.), level of conscious, coordinaton,

balance and vision

vertebral artery

supply blood to the upper spinal cord,

brainstem, cerebellum, and posterior part of

brain

acute ischemic stroke (AIS)

Occlusion of blood flow to the brain Middle cerebral artery is the most commonly occluded in stroke = 70% of cases

• Common MCA stroke symptoms

• motor and sensory deficits

• most commonly face and arms

• aphasia

infarct AIS

“severe ischemia” – blood fow

<25 percent – dead tissue

penumbra AIS

“mild to moderate

ischemia” – area surrounding infarct

transient ishemic attack (TIA)

Blood flow is temporarily blocked from a blood clot, narrow blood vessel, restricted blood flow from carotid arteries

hemorrhagic stroke

Weakened blood vessel bursts

• Pressure from the leaked blood damages

brains cells, and, as a result, the damaged area

is unable to functon properly

intraceberal hemmorhage

The bleeding occurs inside of the brain; this is the most

common type of hemorrhagic stroke

subarachnoid hemorrhage

The bleeding occurs between the brain and the membranes

that cover it.

risk factors ofr intracerebal hemorrhage

• Hypertension – the most common cause.

• Cerebral cavernous malfunctons – when

blood vessels do not form correctly in the

brain.

• Arteriovenous malformations (AVMs) – a

genetic condition where blood vessels form

incorrectly, leading to an abnormally tangled

web

risk factors dor subarahnoid hemorhhage

• AVMs

• bleeding disorders

• head injury and trauma

• blood-thinning medicaton

• a bulge in the wall of a blood vessel called a

cerebral aneurysm