Anatomy - The Eye and Raised Intra-Ocular Pressure

Question 1

What are some leading causes for raised ICP?

Answer 1

1. Brain tumour
2. Hydrocephalus
3. Head injury
4. Meningitis
5. Stroke

Question 2

What does the Monro-Kellie hypothesis state?

Answer 2

The volume of the cranial cavity is constant

Brain tissue, blood and CSF are in dynamic equilibrium and an increase in one must lead to a decrease in another

Question 3

Why can raised ICP compress the optic nerve?

Answer 3

Optic nerve is covered by meninges

Question 4

What are the three meningeal layers which cover the optic nerves?

Answer 4

1. Dura
2. Arachnoid
3. Pia

Question 5

Which meningeal space is filled with CSF?

Answer 5

Sub-arachnoid space

Question 6

The dura mater is the ________ meningeal layer

Answer 6

The dura mater is the toughest meningeal layer

Question 7

Where does the dura mater receive its sensory supply?

Answer 7

Trigeminal nerve

Question 8

What are enclosed within the dura mater?

Answer 8

Dural venous sinuses

Question 9

What is found within the subarachnoid space?

Answer 9

1. CSF
2. Blood vessels

Question 10

Which meningeal layer adheres directly to the brain?

Answer 10

Pia

Question 11

What produces CSF?

Answer 11

Choroid plexus

Question 12

What does the subarachnoid space surround?

Answer 12

1. Brain
2. Spinal cord

Question 13

How much CSF is produced daily?

Answer 13

400-500mls

Question 14

Where can CSF be reabsorbed?

Answer 14

Dural venous sinuses via arachnoid granulations

Question 15

At which vertebral level does the subarachnoid space terminate?

Answer 15

S2

Question 16

Where is the 3rd ventricle found within the cranial cavity?

Answer 16

Midline within diencephalon

Question 17

Where are the left and right lateral ventricles found within the brain?

Answer 17

Left and right cerebral hemispheres

Question 18

Which structure connects the 3rd and 4th ventricles?

Answer 18

Cerebral aqueduct

Question 19

Where can the 4th ventricle be found?

Answer 19

Between cerebellum and pons

Question 20

Decribe the pathway of CSF from production to reabsorption

Answer 20

1. Produced by choroid plexus in lateral ventricles
2. Drains into 3rd ventricle
3. Drains into cerebral aqueduct
4. Drains into 4th ventricle
5. Drains into subarachnoid space
6. Reabsorbed via arachnoid granulations into dural venous sinuses

Question 21

Which nerve palsy causes the eye to look down and out?

Answer 21

Oculomotor

Question 22

Which two septae formed from dura mater divide the cranial cavity?

Answer 22

1. Falx cerebri (sagittal)
2. Tentorium cerebelli (transverse)

Question 23

Why is the trochlear nerve susceptible to damage?

Answer 23

It has the longest intracranial course

Question 24

Palsy of the abducens nerve will lead to paralysis of which muscle?

Answer 24

Lateral rectus

Question 25

What does someone look like with an abducens nerve palsy?

Answer 25

Medial deviation of eye (cannot move in horizontal plane)