Blood supply to brain and spinal cord Part 1: Blood supply to the brain

Question 1

What does the common carotid artery divide into, which division supplies the brain and what does this division travel through to enter the skull and supply the brain

Answer 1

• internal and external carotid artery
• internal supplies brain by entering carotid canal

Question 2

What arteries does the sub-clavian arteries give off that supply that brain and what do they travel through to enter the skull

Answer 2

• vertebral arteries
• travel through foramen magnum

Question 3

blood to the brain

What percentage of cardiac output does the brain receive and what percentage of oxygen in the body does the brain consume?

Answer 3

• 17% cardiac output
• consumes 20% of bodies oxygen

Question 4

What percentage of strokes are:
- ischaemic
- haemorrhagic

Answer 4

• 85% ischaemic
• 15% heamorrhagic

Question 5

What do vertebral and internal carotid arteries connect (anastomose) to form?

Answer 5

circle of willis/cerebral arterial circle

Question 6

circle of willis

What do vertebral arteries anastomose to become, where does this artery supply and how does this basillar artery terminate?

Answer 6

• anastomose to become the basilar artery
• they give off branches that supply the cerebellum and pons
• they terminate by dividing into the two posterior cerebral arteries

Question 7

circle of willis

Once in the skull, what area of the brain do the internal carotid arteries (ICAs) run through and how do the ICAs terminate?

Answer 7

• once in skull run through cavernous sinus
• ICAs terminate by dividing into anterior and middle cerebral arteries

Question 8

circle of willis

what arteries complete the circle of willis around the base of the brain

Answer 8

posterior communicating artery

Question 9

What 3 places do the vertebral arteries supply?

Answer 9

• cranial meningies
• upper spinal cord
• medulla oblongata

Question 10

What 4 places do the basilar arteries supply?

Answer 10

• pons
• internal part of ear
• cerebellum
• midbrain

Question 11

what 2 overarching structures constitute the hindbrain?

Answer 11

brainstem and cerebellum

Question 12

What place do the internal carotid arteries supply in general?

Answer 12

majority of the forebrain

Question 13

anterior middle and posterior cerebral arteries

where do anterior cerebral arteries supply

Answer 13

supply most of the medial and superior surfaces of the brain and frontal pole

Question 14

where do middle cerebral arteries supply

Answer 14

supply lateral surface of the brain and temporal pole

Question 15

where does the posterior cerebral arteries supply

Answer 15

supply the inferior surface ofthe brain and occipital pole

Question 16

Outline why severe neurologic problems or even death occur when large cerebral clots occludes (blocks) major cerebral vessels

Answer 16

1. branches of anterior middle and posterior cerebral arteries anastomose on brain’s surface, however are unable to give enough blood to area of brain tissue supplied by one of the arteries if they are blocked.
2. thus, cerebral ischemia can occur resulting in necrosis of the affected brain tissue

Question 17

what would a blockage of the anterior cerebral artery (ACA) cause?

Answer 17

ischemia to the medial area of the precentral gryus

Question 18

What is found in the pre-central gyrus and thus what would be a symptoms of ACA blockage affecting the pre-central gyrus?

Answer 18

• primary motor areas of the cortex

2 symptoms:
- paralysis of the contralateral side of the body/hemiplegia

Question 19

What would happen to the post-central gyrus if also affected by an ischaemic stroke caused in the ACA

Answer 19

impaired sensation if postcentral gyrus is affected

Question 20

What would a blockage of the Middle cerebral artery (MCA) result in

Answer 20

resulting in ischaemia to the lateral part of the parietal lobe

Question 21

What would be 3 symptoms of an ischaemic stroke of the MCA

Answer 21

• paralysis of the contralateral side of the upper limbs and face, but rest of body can be affected
• if post central gyrus is affected, impaired sensation of upper limb and face
• aphasia (disturbances in speech)

Question 22

What would a blockage of the Posterior cerebral artery (PCA) result in

Answer 22

ischaemia to the visual cortex in the occipital lobe

Question 23

What would be 1 symptoms of an ischaemic stroke of the PCA

Answer 23

• homonymous hemianopia with sparing of macular vision (lost of half vision in both eyes)