Neuroanatomy: Blood Supply/Drainage

Question 1

what is horner’s syndrome

Answer 1

disruption of sympathetic innervation to face

• pupil constriction
• eyelid drooping

Question 2

what percent of ICA blood supply goes to MCA

Answer 2

80

Question 3

What would a stroke affecting the middle cerebral artery territory be most likely to be caused by?

Answer 3

An embolus travelling up from the neck/heart (rather than local thrombosis/ vessel rupture)

Because most blood goes to MCA

Question 4

what runs above the optic chiasm

Answer 4

anterior cerebral artery

Question 5

what connects the 2 anterior cerebral arteries

Answer 5

anterior communicating artery (part of the circle of willis)

Question 6

a branch of ACA winds around corpus callosum, what is this called

Answer 6

pericallosal branch (Located within the corpus callosum sulcus)

Question 7

4 parts of ICA

Answer 7

1. cervical: superiorly from common carotid bifurcation to base of skull
2. petrous: traveling through petrous part of temporal bone via carotid canal but exits into the inside of brain via foramen lacerum
3. cavernous: travels through cavernous sinus
4. cerebral: situated at base of brain
   (most of the branches of ICA from here)

Question 8

Why might an anterior cerebral artery stroke cause paralysis of the contralateral lower limb but spare the upper limb and face?

Answer 8

(homunculus)

lower limb (legs) are controlled by middle of brain which is supplied by MCA not ACA

upper limbs supplied by outer part of parietal - ACA

Question 9

what parts of brain does anterior, middle and posterior cerebral arteries supply

Answer 9

anterior - outer parietal and medial SURFACE of brain up until the parieto-occipital sulcus

middle - middle

posterior - posterior part from parieto-occipital sulcus

Question 10

what part of the brain do vertebral arteries supply

Answer 10

back of brain / brain stem

vertebral–> basilar –> pontine/posterior cerebral

Question 11

how do the vertebral arteries run

Answer 11

they arise from the subclavian

up the transverse foramen from C6

enter foramen magnum

then fuse together to form basilar artery

Question 12

what kind of injury can violent flexion-extension of neck cause

Answer 12

rupture of vertebral artery–> brain stem stroke

Question 13

what is the part of the skull called that the basilar artery rests on after arising from foramen mangum?

Answer 13

clivus

Question 14

what branches arise from basilar artery before it terminates by bifurcating into the 2 posterior cerebral arteries

Answer 14

anterior inferior cerebellar arteries
(posterior inferior cerebellar is a branch of vertebral arteries NOT basilar)

pontine arteries

superior cerebellar arteries

Question 15

what do the posterior communicating arteries connect

Answer 15

the posterior cerebral arteries to the ICA

Question 16

explain cigarette between 2 fingers

Answer 16

cigarette = oculomotor nerve

2 fingers = posterior cerebral artery and superior cerebella artery

Question 17

what is quadriplegia

Answer 17

paralysis of all 4 limbs from neck down

due to occlusion of the pontine paramedian arteries

Question 18

what are arterial watersheds?

Answer 18

Regions that receive dual blood supply from the cerebral arteries

Question 19

Why might someone suffer a watershed infarct after being stung by a wasp

Answer 19

Wasp venom—> blood constrict + prothrombotic –> blood clot

Question 20

why are superficial cerebral veins only visible if the leptomeninges (arachnoid + Pia mater) are present

Answer 20

because the cerebral veins travel within the subarachnoid space

Question 21

where are the sinus located:

• superior and inferior sagittal sinus
• straight
• transverse
• sigmoid

Answer 21

superior sagittal- in the attached margin of falx cerebri

inferior sagittal - in free margin of falx cerebri

straight - posterior to inferior sagittal

transverse - margin of tentorium cerebellli

you have 2 transverses and sigmoid

superior, inferior and straight meet at the confluence of sinus

Question 22

what is Broca’s area

Answer 22

language motor

Question 23

which transverse sinus do the superficial and the deep venous system drain to

Answer 23

• superficial to the right

- deep to the left