T1 L13: Ventricular system and CSF

Question 1

What 2 structures are continuous with the ventricular system of the brain?

Answer 1

The subarachnoid space and central canal

Question 2

What does the mantle layer of the neural tube become?

Answer 2

The brain parenchyma

Question 3

What does the lumen of the neural tube become?

Answer 3

Ventricles and the central canal

Question 4

What does the ependymal layer of the neural tube do?

Answer 4

It lines the ventricles and central canal

Question 5

Which ventricle is surrounded by the Telencephalon?

Answer 5

The lateral ventricles

Question 6

Which ventricles is surrounded by the Diencephalon?

Answer 6

The 3rd ventricle

Question 7

Which ventricle is surrounded by the Metencephalon?

Answer 7

The 4th ventricle

Question 8

Which 4 structures are the lateral ventricles divided into?

Answer 8

The body, anterior horn, posterior horn, and inferior horn

Question 9

Which lobe is the body of the lateral ventricles located?

Answer 9

In the Parietal lobe

Question 10

Which lobe is the anterior horn of the lateral ventricles located?

Answer 10

Frontal lobe

Question 11

Which lobe is the posterior horn of the lateral ventricles located?

Answer 11

In the occipital lobe

Question 12

Which lobe is the inferior horn of the lateral ventricles located?

Answer 12

In the temporal lobe

Question 13

How does the CSF appear on a T1-weighted MRI?

Answer 13

dark

Question 14

What is the function of the corpus pellucidium?

Answer 14

It separates the bodies of the lateral ventircles

Question 15

Where is the corpus collosum compared to the corpus pellucidium?

Answer 15

Corpus collosum sits like a roof above corpus pellucidium

Question 16

Where is the Hippocampus found?

Answer 16

In the floor of the lateral horn

Question 17

How do the lateral ventricles communicate with the 3rd ventricle?

Answer 17

Through the interventricular foramen (Formen of Monro)

Question 18

What 2 structures does the fornix connext?

Answer 18

The mamillary bodies and the hippocampus

Question 19

What separates the 2 Thalami?

Answer 19

The 3rd ventricle

Question 20

Which structure creates the roof of the 3rd ventricle?

Answer 20

The fornix

Question 21

Which structure allows communication between the 3rd and 4th ventricles?

Answer 21

The cerebral aqueduct (aqueduct of Sylvius)

Question 22

What surrounds the 3rd ventricles?

Answer 22

The midbrain

Question 23

What surrounds the 4th ventricle?

Answer 23

The hindbrain

Question 24

What are the 3 foramina that exit into the subarachnoid space?

Answer 24

2x Formain of Luschka

1x Foramina of Magendie

Question 25

Where are the foramina of Luschka?

Answer 25

Lateral. Sit very close to the Cerebellar peduncles

Question 26

Where is the foramina of Magendie?

Answer 26

In the middle, in between the olives

Question 27

What are the top 2 colliculi for?

Answer 27

Eyes

Question 28

What are the bottom 2 colliculi for?

Answer 28

Ears

Question 29

What are the 4 main functions of the CSF?

Answer 29

1. Hydraulic buffer to cushion brain against trauma 2. Vehicle for removal of metabolites from CNS 3. Stable ionic environment for neuronal function 4. Transport of neurotransmitters and chemicals

Question 30

Where is CSF produced?

Answer 30

The choroid plexus

Question 31

Where is the Coracoid plexus found?

Answer 31

Throughout the ventricles

Question 32

What is the function of the Choroid plexus?

Answer 32

It produced CSF and filters blood from branches of the internal carotid and basilar arteries

Question 33

Describe the structure of the Choroid plexus

Answer 33

A capillary network surrounded by cuboidal epithelium

Question 34

How is CSF produced?

Answer 34

Blood is filtered through fenestrated capillaries and components are transported through the cuboidal epithelium and into ventricles

Question 35

What lines the ventricles?

Answer 35

The Ependymal layer of cells

Question 36

What is the function of tight junctions between epithelial cells of the Choroid plexus?

Answer 36

To prevent macromolecules from entering the CSF. Only permeable to H2O and CO2. This forms the blood-CSF barrier

Question 37

Describe the structure of Ependymal cells

Answer 37

Have microvilli to increase surface area. Are full of proteins that allow for active transport of CSF components. They are bidirectional

Question 38

How many proteins are there in CSF?

Answer 38

Tiny amount

Question 39

What is the cisterna Magna?

Answer 39

The subarachnoid space that drains below the cerebellum

Question 40

Where is the subarachnoid space?

Answer 40

Between the pia and arachnoid layer

Question 41

Why is it important that the CSF has contact with the brain parenchyma?

Answer 41

So that electrolytes can be transferred and metabolites can be removed

Question 42

How does CSF appear on a T2-weighted MRI?

Answer 42

White

Question 43

What are arachnoid granulations?

Answer 43

Herniations of the arachnoid membrane through the dura mater into the venous sinuses mainly within the superior sagittal and transverse venous sinuses

Question 44

What is the function of the Arachnoid granulations?

Answer 44

They allow for removal of excess cerebrospinal fluid and metabolites

Question 45

Where is the CSF pressure greater, in the subarachnoid space or the venous sinuses?

Answer 45

In the subarachnoid space which prevents blood pooling in the subarachnoid space

Question 46

What happens to the arachnoid granulations when the pressure is too great?

Answer 46

The tips of the granulations close off and act as a one-way valve so CSF can't get into the arachnoids

Question 47

How much CSF is produced each day?

Answer 47

600-700ml (~0.5ml/min)

Question 48

How much CSF is found in ventricles?

Answer 48

~25ml but its continuously moving and replaced. Excess is absorbed by arachnoid granulations

Question 49

What does yellow/orange/pink CSF indicate?

Answer 49

A subarachnoid bleed (A big bleed affecting the carotid arteries). Indicates the breakdown of RBC's and release of haemoglobin

Question 50

What is Xanthochromia mean in terms of CSF disease?

Answer 50

Yellow/orange/ink CSF

Question 51

What does cloudy/Turgid CSF indicate?

Answer 51

Bacterial meningitis

Question 52

What colour CSF does multiple sclerosis cause?

Answer 52

Cloudy CSF

Question 53

Where on the spine is a lumbar puncture taken and why?

Answer 53

At the lumbar cistern (L3/4) because there is no spinal cord and the dorsa and ventral veins will just move out of the way so there less of a risk of injury

Question 54

At what level is a lumbar puncture taken is children and why?

Answer 54

At L4/5 because there is the possibility you could hit the spinal cord since they're still developing

Question 55

What is Hydrocephalus?

Answer 55

A dilation of the brain ventricles caused by a blocked CSF circulation, impaired absorption, or over secretion. This causes an increase in intracranial pressure

Question 56

What are the symptoms of Hydrocephalus?

Answer 56

Headaches, vomiting, visual disturbances, swelling of the optic disc (papilledema), seizures, altered cognition, balance and coordination problems

Question 57

Is hydrocephalus congenital or aquired?

Answer 57

Both

Question 58

What is non-communicating hydrocephalus?

Answer 58

A failure of communication between ventricles and the arachnoid space because of a a blockage within the ventricular system causing the CSF to stop circulating over the surface of the brain. It's caused by tumour, cysts, stenosis

Question 59

`What is the surgical solution for non-communicating hydrocephalus?

Answer 59

Inserting a shunt to reduce intracranial pressure

Question 60

What is Dandy-Walker syndrome?

Answer 60

A congenital malformation of the cerebellum causing an obstruction within the foramina of the 4th ventricles. It causes symmetrical dilation of the ventricles. In infancy a baby's head will become enlarged and shunt has to be inserted

Question 61

What is communicating hydrocephalus?

Answer 61

An obstruction in the arachnoid villi causing the movement of CSF to be impended. It's caused by impaired absorption following subarachnoid haemorrhage, trauma, or bacterial meningitis