Brain Circulation

Question 1

Cerebral Circulation

Answer 1

> 2 vertebral arteries via transverse foramen in cervical spine
2 internal carotid arteries (front of neck)

Question 2

Circle Of Willis

Answer 2

Anterior
> Internal Carotid splits to middle cerebral artery + anterior cerebral artery
- Anterior cerebral arteries are joined by anterior communicating artery (in theory - blood supply can continue even if one gets blocked)

Posterior
> Vertebral arteries join to form basilar artery (in front of brainstem)
> Basilar divides in upper brainstem to 2 posterior cerebral arteries
> posterior cerebral arteries are connected to circle of Willis via 2 small posterior communicating arteries

*Circle of Willis is supposed to allow blood supply even if occlusion (due to communicating arteries)

Question 3

Middle Cerebral Artery supplies

Answer 3

> Most of outer surface of brain
> Sensorimotor cortex
> Basal Ganglia (movement production)
> Internal capsule (inf. to basal ganglia - all pathways travel through here)
> Broca's area (left frontal lobe)

Question 4

Anterior Cerebral Artery supplies

Answer 4

> Frontal lobe

> Medial sensorimotor cortex

Question 5

Posterior Cerebral artery supplies

Answer 5

> Occipital lobe
Medial aspect of temporal lobe
Thalamus

Question 6

Basilar artery supplies

Answer 6

> Brainstem
Cerebellum
Nuclei of cranial nerves