Meninges

Question 1

What are the three layers of the meninges?

Answer 1

Dura, arachnoid and pia

Question 2

Where is the dura mater?

Answer 2

Outmost layer of the meninges, lying directly beneath the bones of the skull and vertebral column

Question 3

Describe the dura mater

Answer 3

Tough fibrous membrane

Question 4

What are the two layers of the dura mater?

Answer 4

Endosteal - lines inner surface of bones of cranium

Meningeal - lines endosteal layer inside cranial cavity

Question 5

What is present between the two layers of the dura mater?

Answer 5

Dural venous sinuses - responsible for venous vasculature of cranium, draining into the internal jugular veins

Question 6

Describe the arterial supply and venous drainage of the dura mater

Answer 6

Middle meningeal artery and ein

Question 7

What innervates the dura mater?

Answer 7

Trigeminal nerve (V1, V2, V3)

Question 8

What are the two types of haematomas involving the dura mater?

Answer 8

Extradural - between skull and endosteal layer of dura

Subdural - venous blood collects between dura and arachnoid mater

Question 9

What usually causes an extradural haematoma?

Answer 9

Tearing of the middle meningeal artery

Question 10

What does a subdural haematoma result from?

Answer 10

Damage to the cerebral veins as they empty into the dural venous sinuses

Question 11

What does separation of the two layers of the dura mater form?

Answer 11

Dural folds, dural venous sinuses

Question 12

What does the arachnoid mater consist of?

Answer 12

Layers of connective tissue

Question 13

True or False:

The arachnoid is extremely vascular and very well innervated

Answer 13

False

Avascular

No innervation

Question 14

What does the sub-arachnoid space contain?

Answer 14

CSF

Question 15

What are arachnoid granulations?

Answer 15

Small projections of arachnoid mater into the dura which allow CSF to re-enter the circulation via the dural venous sinuses

Question 16

Which is the thinnest meningeal layer?

Answer 16

Pia mater - tightly adhered to the surface of the brain and spinal cord

Question 17

Which is the only covering to follow the contours of the brain?

Answer 17

Pia mater

Question 18

Which layers of the meninges are highly vascularised?

Answer 18

Dura and pia

Question 19

What are two examples of dural folds?

Answer 19

Falx cerebri and tentorium cerebelli

Question 20

What is the purpose of dural folds?

Answer 20

Help to stabilise the brain and act as rigid dividers

Question 21

What are dural venous sinuses?

Answer 21

Venous blood filled spaces created by separation of meningeal from periosteal layer of dura

Question 22

What are some examples of dural venous sinuses?

Answer 22

Cavernous sinus, sigmoid sinus, transverse sinus

Question 23

What are bridging veins?

Answer 23

Veins that connect sub arachnoid space into dural venous sinus

Question 24

Why are subdural haematomas more commonly seen in elderly?

Answer 24

They experience cerebral atrophy so the subdural space increases and the veins that travel across them are longer

Question 25

What is the cause of subarachnoid haemorrhage?

Answer 25

Usually trauma to cerebrial arteries - usually a branch of circle of willis