Cerebrospinal fluid, aqueous humour and intercranial pressure

Question 1

Describe CSF

Answer 1

Clear colourless fluid slightly more viscous than water

Question 2

Where is CSF synthesised?

Answer 2

Choroid plexus in brain ventricles

Question 3

Describe the circulation of the CSF

Answer 3

Produced in lateral and 3rd ventricles and circulates to the 4th ventricle and central canal then into the subarachnoid space before being absorbed into the venous circulation

Question 4

What is the purpose of CSF?

Answer 4

Provide protection to the brain
Supply it with nutrients and remove waste
Homeostatic control- sense pH therefore alter ventilation

Question 5

What is contained in the CSF?

Answer 5

Little protein (15-45mg/dl)
Little immunoglobulin
1-5 cells/ml

Question 6

What is the choroid plexus found?

Answer 6

3rd and 4th and lateral ventricles.

Question 7

What is CSF derived from?

Answer 7

Blood that passes close to the choroid plexus

Question 8

What ions are transported from the blood to create CSF?

Answer 8

Na
Cl
HCO3 (Bicarb)
H2O

Question 9

Where can CSF be accessed to measure?

Answer 9

Lumbar puncture

Cervical (somewhere)

Question 10

How many ventricles are there in the brain?

Answer 10

4

Question 11

What are the 4 ventricles in the brain?

Answer 11

Two lateral ventricles
3rd ventricle
4th ventricle

Question 12

What links the lateral ventricles with the 3rd ventricle?

Answer 12

Interventricular foramina

Question 13

What links the 3rd ventricle to the 4th ventricle?

Answer 13

Cerebral Aqueduct

Question 14

What does the interventricular foramina do?

Answer 14

Link the lateral ventricles to the 3rd ventricle

Question 15

What does the Cerebral Aqueduct do?

Answer 15

Link the 3rd ventricle to the 4th ventricle

Question 16

What do the foramen Magendie and Luschka do?

Answer 16

Link the 4th ventricle to subarachnoid space

Question 17

What links the 4th foramen to the subarachnoid space?

Answer 17

Foramen Magendie and Luschka

Question 18

What extends inferiorly our of the 4th ventricle?

Answer 18

Central canal

Question 19

What does the central canal do?

Answer 19

Carry CSF to the spinal cord

Question 20

Where does CSF return to the venous circulation?

Answer 20

Arachnoid granulations/dura arachnoid vili

Question 21

What separates the blood from the CSF?

Answer 21

Blood CSF barrier

Question 22

What kind of pathologies can affect the ventricles or CSF?

Answer 22

Tumours
Hemorrhage
Hydrocephalus
Idiopathic intracranial hypertension

Question 23

What can brain hemorrhages lead to?

Answer 23

Blood accumulation in the ventricles

Question 24

What is the lay term for hydrocephalus?

Answer 24

Water on the brain

Question 25

What is hydrocephalus?

Answer 25

Accumulation of CSF leading to enlargement of ventricles

Question 26

What is papilloedema?

Answer 26

Swelling of the optic disk due to increased intracranial pressure

Question 27

What are some symptoms of papilloedema?

Answer 27

Enlarged blind spot Blurred vision Loss of vision

Question 28

What is aqueous humour?

Answer 28

Fluid that fills the anterior chamber of the eye

Question 29

What does aqueous humour do?

Answer 29

Supplies oxygen, metabolites and bicarb to the cornea and iris etc

Question 30

What is the importance of the bicarb in aqueous humour?

Answer 30

To buffer the H+ produced by anaerobic met in the cornea

Question 31

What is ascorbate?

Answer 31

A strong antioxidant

Question 32

Why is ascorbate found in the aqueous humour?

Answer 32

To help protect the eye from anaerobic met

Question 33

What ions are found in aqueous humour?

Answer 33

Na | Cl

Question 34

What is an overproduction of aqueous humour called?

Answer 34

Glaucoma

Question 35

What is glaucoma?

Answer 35

Overproduction of aqueous humour

Question 36

What medication types can be used to prevent glaucoma?

Answer 36

Carbonic Anhydrase Inhibitors

Question 37

Why do CA Inhibitors help prevent glaucoma?

Answer 37

Block CA which in turn prevents Na uptake

Question 38

Give some examples of CA Inhibitors used in glaucoma

Answer 38

Dorzolamide | Acetazolomide

Question 39

How is dorzolamide administered?

Answer 39

Eye drops

Question 40

How is acetazolomide administered?

Answer 40

Oral- kidney problems

Question 41

What can cause raised intracranial pressure?

Answer 41

Tumours, abscess, hemorrhage Hydrocephalus Meningitis

Question 42

What are the three layers of the meninges?

Answer 42

Dura mater- Durable mother Arachnoid mater- Spider like Pia mater- Soft mother

Question 43

What flows in the subarachnoid space?

Answer 43

CSF

Question 44

What is the dura mater a continuation of?

Answer 44

Periosteum of cranial cavity

Question 45

Are the meninges restricted to the contours of the skull or can they dive down into the sulci?

Answer 45

Dive down into the sulci

Question 46

What does the dura mater form in the sulci of the brain?

Answer 46

Falx cerebri | Cerebellar tentorium

Question 47

What is the falx cerebri?

Answer 47

Invagination of dura mater in the longitudinal fissure

Question 48

What does falx mean?

Answer 48

SIckle

Question 49

What are the cerebellar tentorium?

Answer 49

Invagination of dura mater between the cerebellum and occipital lobes of cerebrum

Question 50

What runs along the edge of the cerebellar tentorium?

Answer 50

Several nerves associated with the eye

Question 51

What passes through the hole in the cerebellar tentorium?

Answer 51

Brainstem

Question 52

What can be found between layers of the dura mater?

Answer 52

Dural venous sinuses

Question 53

What are dural venous sinuses?

Answer 53

SInuses of venous blood without vein walls

Question 54

What happens in the Arachnoid granulations/dura arachnoid vili?

Answer 54

CSF returned to venous blood

Question 55

Where are Arachnoid granulations/dura arachnoid vili found?

Answer 55

Dura venous sinuses

Question 56

Why can raised intracranial pressure lead to visual disturbances?

Answer 56

Because meninges and subarachnoid space extend along the optic nerve to the eye

Question 57

What extends along the optic nerve to the eye?

Answer 57

Meninges and subarachnoid space

Question 58

Why can raised intracranial pressure lead to visual disturbances?

Answer 58

Because meninges and subarachnoid space extend along the optic nerve to the eye

Question 59

What extends along the optic nerve to the eye?

Answer 59

Meninges and subarachnoid space

Question 60

What visual disturbances can raised intracranial pressure cause?

Answer 60

``` Transient blurred vision Double vision- Diplopia Loss of vision Papilloedema- Swelling of optic disk Pupillary changes ```

Question 61

What is diplopia?

Answer 61

Doube vision

Question 62

What is the correct term for a swelling of the optic disk due to raised intracranial pressure?

Answer 62

Papilloedema

Question 63

How many eyes can raised ICP affect

Answer 63

One or both

Question 64

What is the correct term for a swelling of the optic disk due to raised intracranial pressure?

Answer 64

Papilloedema

Question 65

How many eyes can raised ICP affect

Answer 65

One or both

Question 66

What are some of the symptoms of trochlear nerve damage?

Answer 66

Eye cannot move inferomedially | Diplopia when looking down

Question 67

What are some symptoms of oculomotor nerve damage?

Answer 67

No/slow pupillary light reflex Dilated pupil Ptosis Position of eye: looking ‘down and out’

Question 68

What are some of the symptoms of trochlear nerve damage?

Answer 68

Eye cannot move inferomedially | Diplopia when looking down

Question 69

What is the symptom of abducens nerve damage?

Answer 69

Medial deviation of the eye