11 - Cranial nerves and blood supply to the brain

Question 1

How does the subclavian artery enter the cranium?

Answer 1

• vertebral branch enters the cranium via the transverse foramina and the foramen magnum
• joins the basilar artery to provide the posterior of the brain

Question 2

Describe what the ICA supplies in the cranium.

Answer 2

• iCA provides middle and anterior cerebral arteries for anterior supply of brain
• enters cranium via the carotid canal

Question 3

Where does the ECA supply in the cranium?

Answer 3

Provides meninges via middle meningeal artery (maxillary branch)

Question 4

What are the intracranial branches of the ICA?

Answer 4

• middle cerebral artery
• anterior cerebral artery
• ophthalmic artery

Question 5

What are the intracranial branches of the ECA?

Answer 5

• maxillary artery
• middle meningeal artery
• ascending pharyngeal artery
• occipital

Question 6

What are the intracranial branches vertebral artery?

Answer 6

• basilar artery
• posterior cerebral artery

Question 7

What is the circle of willis?

Answer 7

• anterior to where the basilar artery crosses the pons and the vertebral artery crosses the medulla
• where the cerebral arteries branch

Question 8

Where does the anterior cerebral artery supply?

Answer 8

Medial side of frontal lobe

Question 9

Where does the middle cerebral artery supply?

Answer 9

• lateral side of the frontal lobe
• lateral side of the temporal lobe

Question 10

Where does the posterior cerebral artery supply?

Answer 10

Lateral and medial side of the occipital lobe

Question 11

How does stroke affect the anterior cerebral artery?

Answer 11

• contralateral hemiparesis and hemisensory loss (mainly leg and foot)
• unable to identify objects
• personality change

Question 12

How does stroke affect the middle cerebral artery?

Answer 12

• contralateral hemiparesis and hemisensory loss (mainly face and arm)
• aphasia (LHS)
• contralateral homonymous hemianopia
• anosognosia (lack of insight)

Question 13

How does stroke affect the posterior cerebral artery?

Answer 13

• contralateral homonymous hemianopia
• visual agnosia
• memory impairment

Question 14

Describe the dural venous sinuses.

Answer 14

• spaces between periosteal and meningeal layers of dura
• endothelium lined
• venous drainages of brain and CSF resorption via arachnoid granulation

Question 15

What are the dural septa?

Answer 15

• falx cerebri
• falx cerebelli
• diaphragma sellae
• tentorium cerebelli

Question 16

Describe the confluence of sinuses.

Answer 16

• found at the posterior of the cranium
• where the straight sinus, superior sagittal and transverse sinuses meet

Question 17

What are the main venous sinuses in the cranium?

Answer 17

• sigmoid
• L/R transverse
• straight
• superior sagittal
• cavernous
• intercavernous
• petrosal

Question 18

Describe the cavernous sinus.

Answer 18

• one sinus made up of lots of small vessels
• blood flows very slowly here
• venous drainage of the face and mouth

Question 19

What is cavernous sinus thrombosis?

Answer 19

• blood clot in the cavernous sinus
• can be caused by infection within the danger triangle

Question 20

What causes an extradural haematoma?

Answer 20

• fractures or trauma
• loss of consciousness takes a few days

Question 21

What causes a subdural haematoma?

Answer 21

• older age (falls, not fractures)
• venous bleeds are slow and take weeks to present

Question 22

What causes subarachnoid haemorrhage?

Answer 22

• associated with aneurysm
• affects any age group
• loss of consciousness very quick