Blood supply to brain and spinal cord Part 1: Blood supply to the brain Flashcards
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
- internal and external carotid artery
- internal supplies brain by entering carotid canal
What arteries does the sub-clavian arteries give off that supply that brain and what do they travel through to enter the skull
- vertebral arteries
- travel through foramen magnum
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?
- 17% cardiac output
- consumes 20% of bodies oxygen
What percentage of strokes are:
- ischaemic
- haemorrhagic
- 85% ischaemic
- 15% heamorrhagic
What do vertebral and internal carotid arteries connect (anastomose) to form?
circle of willis/cerebral arterial circle
circle of willis
What do vertebral arteries anastomose to become, where does this artery supply and how does this basillar artery terminate?
- 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
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?
- once in skull run through cavernous sinus
- ICAs terminate by dividing into anterior and middle cerebral arteries
circle of willis
what arteries complete the circle of willis around the base of the brain
posterior communicating artery
What 3 places do the vertebral arteries supply?
- cranial meningies
- upper spinal cord
- medulla oblongata
What 4 places do the basilar arteries supply?
- pons
- internal part of ear
- cerebellum
- midbrain
what 2 overarching structures constitute the hindbrain?
brainstem and cerebellum
What place do the internal carotid arteries supply in general?
majority of the forebrain
anterior middle and posterior cerebral arteries
where do anterior cerebral arteries supply
supply most of the medial and superior surfaces of the brain and frontal pole
where do middle cerebral arteries supply
supply lateral surface of the brain and temporal pole
where does the posterior cerebral arteries supply
supply the inferior surface ofthe brain and occipital pole
Outline why severe neurologic problems or even death occur when large cerebral clots occludes (blocks) major cerebral vessels
- 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.
- thus, cerebral ischemia can occur resulting in necrosis of the affected brain tissue
what would a blockage of the anterior cerebral artery (ACA) cause?
ischemia to the medial area of the precentral gryus
What is found in the pre-central gyrus and thus what would be a symptoms of ACA blockage affecting the pre-central gyrus?
- primary motor areas of the cortex
2 symptoms:
- paralysis of the contralateral side of the body/hemiplegia
What would happen to the post-central gyrus if also affected by an ischaemic stroke caused in the ACA
impaired sensation if postcentral gyrus is affected
What would a blockage of the Middle cerebral artery (MCA) result in
resulting in ischaemia to the lateral part of the parietal lobe
What would be 3 symptoms of an ischaemic stroke of the MCA
- 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)
What would a blockage of the Posterior cerebral artery (PCA) result in
ischaemia to the visual cortex in the occipital lobe
What would be 1 symptoms of an ischaemic stroke of the PCA
- homonymous hemianopia with sparing of macular vision (lost of half vision in both eyes)
