L12-Ventricular System

Question 1

Where is the septum pellucidum? What structures lies above?

Answer 1

Separates lateral ventricles
Contains both white and grey matter

above is corpus callosum

Question 2

What forms the basal ganglia?

Answer 2

Lentiform nucleus and caudate nucleus

Question 3

What is the foramen of Monro

Answer 3

Aka interventricular foramen

Communication between the lateral ventricles and third ventricles

Question 4

Where is the Third ventricle

Answer 4

Slit like cleft between thalami

Question 5

What is the cerebral aqueduct

Answer 5

Communication between third and fourth ventricle

Surrounded by mesencephalon (midbrain)

Question 6

How does the fourth ventricle communicate

Answer 6

2 foramen of luschka

1 foramen of magendie

Question 7

What is the choroid plexus?

Answer 7

Filtration system that produces CSF

ABOUT 60% produced here

Question 8

Describe CSF production

Answer 8

Blood is filtered through fenestrated capillaries

Transport of components across epithelium cells into ventricles

Question 9

What is the importance of the tight junctions between the epithelial cells?

Answer 9

Forms blood-CSF barrier

Prevents macromolecules from entering CSF

Question 10

What is the functional importance of the subarachnoid space?

Answer 10

• transfer of micronutrients into brain

- removal of metabolites

Question 11

What must occur before CSF can be absorbed?

Answer 11

CSF pressure must be higher than pressure in venous sinuses

Question 12

What are the main functions of CSF?

Answer 12

1. Hydraulic buffer to cushion brain against trauma
2. Vehicle for removal of metabolites from CNS
3. Stable ionic environment for neuronal function
   (communicates with brain interstitial fluid via pia)
4. Transport of neurotransmitters and chemicals

Question 13

What can yellow CSF suggest

Answer 13

Subarachnoid haemorrhage due to bilirubin

Question 14

What can cloudy CSF suggest?

Answer 14

Multiple sclerosis

Bacterial meningitis

Question 15

What is hydrocephalus

Answer 15

Water in the ventricles

Due to impaired CSF circulation

Question 16

What is dandy-walker syndrome

Answer 16

Congenital form of non-communicating hydrocephalus
Cerebellum doesn’t grow
All ventricles are dilated

Question 17

What is non-communicating hydrocephalus?

-how would you treat

Answer 17

Blockage within the ventricular system

-Insert shunt to reduce intracranial pressure

Question 18

What is communicating hydrocephalus?

How may it occur?

Answer 18

Obstruction in the arachnoid villi

• Movement of CSF into venous sinuses is impeded
• E.g. Impaired absorption following subarachnoid haemorrhage, trauma or bacterial meningitis

Question 19

What is the name of the layer that lines the ventricles?

Answer 19

Ependymal layer

Question 20

Where do the ventricles and canals arise (embryology)? From which layer does this arise?

Answer 20

lumen of neural tube

from neuroectoderm

Question 21

Telencephalon

Answer 21

cerebral hemispheres

• cerebral hemispheres
• lateral ventricles