Cranial Fossae, Meninges, venous sinuses and bleeds

Question 1

what is the space outside of the dura mater called?

Answer 1

extra dural space

Question 2

what are the three layers of meninge?

Answer 2

Dura mater, Arachnoid Mater, and Pia mater

Question 3

what does meninx mean?

Answer 3

membrane

Question 4

What is ‘genio’ latin for?

Answer 4

chin

Question 5

what are the two layers of the dura mater?

Answer 5

periosteal layer

meningeal layer

Question 6

where is the meningeal layer of the dura mater often adhered to?

Answer 6

it’s often adherent to the periosteal layer of the dura mater

though, the layer does move away form this periosteal layer often and it forms a compartment in the brain creating the falx cerebelli and falx cerebri and the tenorium cerebelli

Question 7

as a result of the infolding of the meningeal layer of the dura mater, what do we get?

Answer 7

the tentorium cerebelli, falx cerebri, and falx cerebelli -

Question 8

As a result of the gaps between the dura, where does venous blood move through?

Answer 8

the dura mater then contains ‘dural sinuses’ which are channels for venous drainage of the brain

Question 9

where does the superior sagittal sinus run? Where does the inferior sagittal sinus run? What joins the two?

Answer 9

Question 10

what are the sinuses of the dura of the brain?

Answer 10

inferior sagittal

superior sagittal

straight

right transverse

sigmoid

inferior petrosal

superior petrosal

cavernous sinus

Question 11

The sigmoid sinus is continuous with what large vein?

Answer 11

it is continuous with the internal jugular vein

Question 12

what plexus drains into the caverna sinus?

Answer 12

the pterigoplexus and the opthalmic veins

Question 13

The cavernous sinus contains what?

Answer 13

internal carotid

abducens nerve (6)

maxillary nerve (5b)

opthalmic nerve (5a)

trochlear nerve (4)

oculomotor nerve(3)

Question 14

what is the role of the 3rd cranial nerve?

Answer 14

-Occulomotor- responsible for the pupillary reflex

and motor innervation for four muscles of the eye

Question 15

What muscle of the eye does trochlear nerve innervate?

Answer 15

Superior O….

Question 16

What does the opthalmic and Maxillary devision of the trigeminal never

Answer 16

opthalmic looks after sensation of the forehead

Maxillary looks after sensation of the cheeks

Question 17

What does the abducens nerve innervate?

Answer 17

LR6

it abducts the eyes

Question 18

why do we call the region of the nose and the upper cheeks the ‘danger zone’

Answer 18

b/c if a clot is formed in this region, the patient will experience

• loss of sensation of the forehead and cheek
• papillary reflex lost
• loss of movement of the eye
• opthalmic exosthalmic? protrusion of the eyeball

Question 19

where do the superior and inferior petrosal sinuses drain into?

Answer 19

superior petrosal drains into transverse sinus

inferior petrosal drains into the sigmoid sinus

Question 20

between the cerebellum and the posterior cerebrum, what space sits between them?

Answer 20

the tentorium cerebelli

Question 21

where is the cerebrospinal fluid produced?

Answer 21

in the ventricles -

Question 22

what is the lateral ventricle made up of?

Answer 22

anterior horn of lateral ventricle, body of lateral ventricle, and the posterior horn of the lateral ventricle

Question 23

a lot of the CSF will pass out of what foramen into the subarachnoid space?

Answer 23

out of the foramen Magendie and the Foramina of Lushka

Question 24

where is the CSF primarily reabsorbed into circulation?

Answer 24

superior sagittal sinus- by the ingrowth into the sinus called arachnoid villi/granulations

Question 25

as the mater sweeps over the brain and brainstem - there are larger gaps between the subarachonoid space and the brain itself - this makes larger gaps for pooling blood called the ‘cisterns’ - what are the ‘cisterns’ in the brain?

Answer 25

•

•Cisterns

–Interpeduncular

–Pontine

–Quadrigeminal

–Cisterna magna

Question 26

where do you find the interpeduncular cistern and the cisterna magna?

Answer 26

Question 27

where does an extradural haematoma usually occur?

Answer 27

–Usually in temporal / tempero parietal region

–Occasionally results from damage to sagittal / transverse sinus

• May have short period of Loss of consciousness
• Lucid interval- fully oriented, they know who they are and what day it is etc…
• Rapid deterioration within 24 hours

Question 28

are extradural haematomas venous or arterial?

Answer 28

most of the time they are arterial - unles shtey result from a tear to the sinus in which case they are venous

Question 29

subdural haematomas- are they acute or chronic?

Answer 29

they are usually associated with a chronic syndrome- predominantly occur in infancy and in the elderly

trauma is likely to be a cause of this, although a hisotry of this is not always obtained (ex. in an older person, they may have hit their head against a door and this normally wouldn’t be a problem, but they have atrophy of the brain and a small trauma may be enough to tear the subdural space

Question 30

what is hydrocephalis?

Answer 30

enlargement of the ventricles

Question 31

Chronic subdural haematomas are specific or non-specific

Answer 31

they are usually non-specific associatedd with chronic venous bleeds - though they could potentially present accutely

Question 32

from what does a subarachnoid haemorrhage develop?

Answer 32

bleedig from the intracranial vessels in the subarachnoid space - usually associated with aneurysms (usually weakening in tunica media muscle wall)

Question 33

are subarachnoid haemorrhages acute or chronic?

Answer 33

usually they are acute - associated with a transient or prolonged loss of consciousness - they’ll describe it as a sudden ‘worst headache you’ve ever experienced’

over the a couple days you’ll see neck stiffness, decreased consciousness, seizures, papilloedema (swelling at back of eye), reactive hypertension, and pyrexia (temperature)