Topic 4 - cerebral circulation

Question 1

what are the three main branches of the aortic arch

Answer 1

brachiocephalic artery
left common carotid
left subclavian

Question 2

what does the subclavian artery supply

Answer 2

blood to the CNS, arms, chest, shoulders, and back

Question 3

which arteries branch off the subclavian to supply blood to the brain

Answer 3

common carotid and vertebral arteries

Question 4

what is the difference between the internal and external carotid

Answer 4

external carotid = supplies blood to the face, neck,and lower jaw

internal carotid = contains the baro and chemoreceptors, mainly supplies blood to the middle and anterior portions of the brain

Question 5

what is the benefit of having two separate sets of receptors (external carotid and aorta)

Answer 5

two measures of pressure and chemical concentration
- really important to keep control of what gets into the brain

Question 6

what supplies blood to the occipital lobe / back of the brain

Answer 6

paired vertebral arteries join together to form the large basilar artery at the base of the medulla oblongata

Question 7

what is the importance/benefit of the circle of willis

Answer 7

allows the re routing of blood in the brain if there is a blockage

Question 8

what is the difference in supply to the brain between the internal carotid and vertebral artery

Answer 8

internal carotid:
- feeds into MCA and ACA
- supplies 75% of brain (front)

vertebral:
- feeds into PCA
- supplies 25% of the brain (back - mainly occipital, little temporal and parietal)