Blood Supply, Venous Drainage and Cranial Nerves

Question 1

what are the main 2 sources of blood supply to the brain

Answer 1

vertebral and internal carotid artery

Question 2

what is the pathway of the vertebral artery

Answer 2

subclavian - vertebral - transverse foramina of C1-C6 - foramen magnum and cranial cavity

Question 3

what forms the basilar artery

Answer 3

left and right vertebral arteries

Question 4

what supplies the anterior and middle parts of brain

Answer 4

internal carotid artery

Question 5

what does the external carotid artery supply

Answer 5

the meninges via the middle meningeal artery

Question 6

where does the middle meningeal artery run

Answer 6

between the bone and the dura at the pterion

Question 7

what does the circle of willis supply

Answer 7

anterior, middle and posterior brain

Question 8

where does the circle of willis lie

Answer 8

around the optic chiasm and pituitary stalk

Question 9

where does the basilar artery lie

Answer 9

over the pons

Question 10

what do the posterior cerebral arteries supply

Answer 10

posterior brain (occipital lobe)

Question 11

what do the posterior communicating arteries do

Answer 11

communicate with anterior and middle part of circulation in circle of willis

Question 12

what does the middle cerebral artery supply

Answer 12

the internal capsule via small lenticular striate arteries, temporal lobe, parietal lobe, frontal lobe

Question 13

what do the anterior cerebral arteries supply

Answer 13

medial side of the cranial hemisphere and anterior part of brain

Question 14

if there is a stroke in the anterior cerebral artery supplying the front of the brain, what is affected

Answer 14

lower limbs, personality, cant identify objects

Question 15

if there is a stroke in the middle cerebral artery supplying the temporal, parietal and frontal lobe and internal capsule, what is affected

Answer 15

brocas and wernickes (aphasia), face and upper limb

Question 16

if there is a stroke in the posterior cerebral artery supplying the occipital lobe what is affected

Answer 16

vision, memory

Question 17

what are dural venous sinuses

Answer 17

spaces between perisosteal and meningeal layers of dura mater

Question 18

what occurs in the dural venous sinuses

Answer 18

venous drainage and CSF resorption

Question 19

once the CSF circulates in the ventricles, what happens to it

Answer 19

goes into subarachnoid space, absorbed through arachnoid granulations and then into superior sagittal sinus

Question 20

what are the main sinuses

Answer 20

superior sagittal sinus, sigmoid sinus, cavernous sinus, transverse sinus

Question 21

where does the superior sagittal sinus run

Answer 21

in the falx cerebelli to the back where the falx meets the tentorium cerebelli

Question 22

where does the superior sagittal sinus split at the posterior aspect of the brain

Answer 22

at the conference of sinuses into left and right transverse sinus

Question 23

where does the transverse sinus run

Answer 23

within the tentorium cerebelli and along the base of the skull to drain into the jugular foramen

Question 24

where does all venous drainage go

Answer 24

into the IJV

Question 25

where does the cavernous sinus run

Answer 25

beside the sellae turcica

Question 26

why is the blood supply slow in the cavernous sinus

Answer 26

because there are lots of small channels

Question 27

how does a cavernous sinus thrombosis happen

Answer 27

because the slow blood supply gives the bacteria spread from the danger zone time to multiply

Question 28

what does a cavernous sinus thrombosis cause

Answer 28

fever and swollen eyes

Question 29

what causes a cavernous sinus thrombosis

Answer 29

injury/infection of the face/upper teeth

Question 30

why does an epidural haematoma occur

Answer 30

due to rupture of the middle meningeal artery at pterion, associated with fracture/trauma

Question 31

which type of haematoma would loss of consciousness be quick and why

Answer 31

epidural haematoma - anterior bleed

Question 32

what is a subdural haematoma associated with

Answer 32

age as tissues are less sturdy and if there is a fall it can be strong enough to rupture the brains blood vessels

Question 33

how long does it take to develop symptoms of a subdural haematoma and why

Answer 33

a few weeks as it is a slow bleed because it is venous

Question 34

what happens in a subarachnoid haemorrhage

Answer 34

one of the arteries within the circle of willis ruptures

Question 35

what is a subarachnoid haemorrhage associated with

Answer 35

aneurysm

Question 36

where do subarachnoid haemorrhages occur

Answer 36

where the junction between arteries is - where the arterial wall is weaker so an aneurysm can easily burst in subarachnoid space

Question 37

where do the olfactory and optic nerves come from

Answer 37

forebrain

Question 38

what are the 5 main functions that a cranial nerve could have

Answer 38

motor fibres to voluntary muscle
motor fibres to involuntary muscle
general sensation
visceral sensation
special sensation

Question 39

what does the spinal accessory nerve innervate

Answer 39

SCM and trapqezius

Question 40

what cranial nerve passes through the nose

Answer 40

1 (olfactory)

Question 41

what cranial nerve passes to the orbit

Answer 41

optic, occulomotor, trochlear, trigeminal ophthalmic, abducens

Question 42

what cranial nerve passes to the front of the face

Answer 42

trigeminal maxillary

Question 43

what cranial nerve passes through the base of the skull

Answer 43

trigeminal mandibular, facial, glossopharyngeal, vagus, accessory, hypoglossal

Question 44

where does the circle of willis lie

Answer 44

around the optic chiasm and pituitary stalk