Anatomy of Space Occupying Lesions

Question 1

From which cranial nerve does the dura mater receive its sensory nerve supply?

Answer 1

CNV

Question 2

What is the function of the arachnoid granules within the arachnoid mater?

Answer 2

Reabsorb CSF (into the dural venous sinuses)

Question 3

What is the tentorium cerebelli?

Answer 3

Tough sheet of dura mater over the cerebellum - central gap for brainstem

Question 4

Where does the tentorium cerebelli attach?

Answer 4

To the ridges of the petrous temporal bones

Question 5

What is the diaphragm sellae?

Answer 5

Tough sheet of dura mater which forms a roof over the pituitary fossa

Question 6

What is the faux cerebri?

Answer 6

Sheet of dura mater in the midline which separates the right and left hemispheres

Question 7

Where do the dural venous sinuses ultimately drain?

Answer 7

Internal jugular vein at jugular foramen

Question 8

What veins join at the confluence of sinuses?

Answer 8

Superior sagittal sinus
Inferior sagittal sinus
Straight sinus

Question 9

What arteries supply the brain?

Answer 9

Vertebral

Internal carotid

Question 10

What artery does the vertebral artery branch from?

Answer 10

Subclavian artery

Question 11

What arteries make up the circle of Willis?

Answer 11

Anterior cerebral 
Posterior cerebral
Internal carotid
Anterior communicating
Posterior communicating 

(middle cerebral are NOT part of the circle)

Question 12

What does the subarchnoid space contain?

Answer 12

CSF

Question 13

Where is CSF produced?

Answer 13

By epithelial cells in choroid plexus of ventricles

Question 14

Where does the subarachnoid space end?

Answer 14

L2

Question 15

Where can the subarachnoid space be accessed? Via lumbar puncture

Answer 15

L3/L4

L4/L5

Question 16

Describe the circulation of CSF (8 steps)

Answer 16

1. Secreted by epithelial cells in choroid plexus
2. From right and left ventricles via right and left foramen of Monroe
3. Into 3rd ventricle
4. Via cerebral aqueduct
5. Into 4th ventricle
6. Mainly into subarachnoid space but some into central canal
7. Reabsorbed by arachnoid granulations
8. Into dural venous sinuses

Question 17

What is hydrocephalus?

Answer 17

Increased CSF volume

Question 18

What is the management of hydrocephalus?

Answer 18

Ventricular peritoneal shunt

Question 19

What are the 3 types of haemorrhage that can occur in cranial cavity?

Answer 19

Extradural
Subdural
Subarachnoid

Question 20

What is an extradural haemorrhage and a likely cause?

Answer 20

Bleeding between bone and dura

Ruptured middle meningeal artery - usually due to trauma

Question 21

What is a subdural haemorrhage and a likely cause?

Answer 21

When blood causes dura to separate from arachnoid

Torn cerebral veins - usually due to falls in elderly

Question 22

What is a subarachnoid haemorrage and a likely cause?

Answer 22

When blood haemorrages into CSF of subarachnoid space

Ruptured circle of Wills - berry aneurysm