brain blood vessels - blood supply to the CNS & intracerebral bleeds

Question 1

what 2 paired arteries are responsible for blood supply to the brain?

Answer 1

-vertebral artery
-internal carotid arteries

Question 2

which artery is the vertebral artery a branch of?

Answer 2

the subclavian artery

Question 3

what artery is the internal carotid artery a branch of?

Answer 3

• branch of common carotid artery

Question 4

what do the terminal branches of these 2 paired arteries form in the brain?

Answer 4

terminal branches of these arteries form an anastomotic circle, called the Circle of Willis

Question 5

at what vertebral level does the common carotid artery bifurcate?

Answer 5

C4

Question 6

through which ‘canal’ does the ICA ascend into the brain?

Answer 6

• carotid canal

Question 7

once the ICA has entered the cranial cavity, what structure does it pass through?

Answer 7

passes through the cavernous sinus anteriorly

Question 8

what are the branches of the ICA?

Answer 8

-ophthalamic artery
-anterior choroidal artery
-posterior communicating artery
-2 terminal branches : anterior and middle cerebral artery

Question 9

what does the ophthalmic artery supply?

Answer 9

supplies structures of the orbit

Question 10

what does the anterior choroidal artery supply?

Answer 10

supplies structures in the brain important for motor control and vision.
-also supplies optic chiasma, optic tract, lateral geniculate etc

Question 11

what’s the function of the posterior communicating artery ?

Answer 11

acts as an anastomotic ‘connecting vessel’ in the Circle of Willis

Question 12

where do the arteries lie within the 3 layers of the meninges?

Answer 12

the subarachnoid space

Question 13

what are the branches of the vertebral artery?

Answer 13

-PICA - posterior inferior cerebellar artery
-anterior spinal arteries
-posterior spinal arteries
-meningeal branch

Question 14

what does the meningeal branch of the vertebral artery supply?

Answer 14

falx cerebelli, a sheet of dura mater.

Question 15

what do the anterior and posterior spinal arteries supply?

Answer 15

supplies the spinal cord, spanning its entire length.

Question 16

what does the PICA artery supply?

Answer 16

the cerebellum

Question 17

once the vertebral arteries branch out, what do they do?

Answer 17

the two vertebral arteries converge to form the basilar artery

Question 18

through what foramen does the vertebral arteries ascend into the cranial cavity ?

Answer 18

foramen magnum

Question 19

what does the basilar artery supply?

Answer 19

-posterior circulation of brain
-goes along the midline of the pons

Question 20

what are the branches of the basilar artery? ALPS

Answer 20

-AICA - anterior inferior cerebellar arteries
-labryrinthine arteries
-pontine arteries
-superior cerebellar arteries

Question 21

what is the circle of willis?

Answer 21

a circle - in which the internal carotid artery and vertebral arteries anastomose and communicate with each other

Question 22

what are the 3 main paired arteries of the circle of willis?

Answer 22

-Anterior cerebral arteries – terminal branches of the internal carotid arteries.
-Internal carotid arteries – located immediately proximal to the origin of the middle cerebral arteries.
-Posterior cerebral arteries – terminal branches of the basilar artery

Question 23

what are the 2 connecting vessels in the circle of willis?

Answer 23

-Anterior communicating artery – connects the two anterior cerebral arteries.
-Posterior communicating artery – branch of the internal carotid, this artery connects the ICA to the posterior cerebral artery.

Question 24

what are the 3 cerebral arteries?

Answer 24

-anterior
-middle
-posterior

Question 25

what part of the CNS does the anterior cerebral artery supply?

Answer 25

-orbital surface of frontal lobe
-medial aspect of hemisphere
-upper border of frontal and parietal lobes

Question 26

what part of the brain does the middle cerebral artery supply?

Answer 26

-lateral aspect of the cerebral hemisphere except occipital lobe
-thorax, upper limb, head and neck - speech & auditory

Question 27

functionally, what areas of the body might a blockage of the anterior cerebral artery in a stroke affect?

Answer 27

-lower limb - sensory and motor loss
-perineum / pelvic area - micturition and defecation

Question 28

functionally, what areas of the body / functions of body might be affected by a blockage of the middle cerebral artery?

Answer 28

-head and neck - speech and auditory function
-weakness and paralysis on the opposite side of the body
-numbness & loss of sensation on one side of the body

Question 29

what do the medial striate arteries supply?

Answer 29

-internal capsule (important structure transmitting motor and sensory information between the cerebral cortex and the brainstem/spinal cord.)
-near the basal ganglia - head of caudate, medial globes pallidus etc

Question 30

what do the lateral striate arteries supply?

Answer 30

-internal capsule
-basal ganglia - putamen

Question 31

define stroke

Answer 31

sudden death of brain cells due to lack of oxygen, caused by the blockage of blood flow or rupture of an artery to the brain

Question 32

what can cause ischaemia of brain cells?

Answer 32

-thrombosis (clot in one of the cerebral arteries)
-embolism (generated in vessel outside of brain eg carotid artery)
-hypertension
-rupture of blood vessels
-trauma
-aneursym

Question 33

what symptoms would occur in a cerebral hemisphere stroke - compare anterior cerebral vs middle cerebral?

Answer 33

-anterior cerebral - contralateral hemiplegia & anaesthesia - lower limb (paralysis affecting 1 part of body)
-middle cerebral - contralateral hemiplegia and anaesthesia - upper limb & thorax - also brocas or wernickes aphasia - damage to speech / auditory

Question 34

what symptoms can occur with posterior cerebral arterial stroke?

Answer 34

contralateral hemianopia (loss of 1/2 of visual field)

Question 35

what are signs of a cerebral hemisphere stroke?

Answer 35

-ipsilateral symptoms - same side of body
-cerebellar signs eg loss of balance & co-ordination

Question 36

what is lateral medullary syndrome / PICA?

Answer 36

-syndrome caused by damage to the lateral part of the medulla oblongata
-symptoms eg ipsilateral pain and temp loss from face (trigeminal nucleus)
-vertigo, tinnitus - vestibulocochlear nuclei
-ipsilateral horners syndrome

Question 37

what is medial medullary syndrome?

Answer 37

neurological condition caused by damage or infarction of the medial part of the medulla oblongata in the brainstem.

Question 38

what are examples of symptoms of medial medullary syndrome?

Answer 38

• contralateral hemiparesis - muscle weakness on 1 side
• contralateral loss of sensation eg fine touch
  -ipsilateral paralysis of tongue