Ventricular System

Question 1

What is the ventricular system?

Answer 1

A series of CSF-filled interconnected spaces which are continuous with the subarachnoid space and central canal.

Question 2

In embryology, what is the brain and spinal cord derived from?

Answer 2

The brain and spinal cord come from the neural tube (which is formed from the neuroectoderm)

Question 3

How many lateral ventricles are there?

Answer 3

2 (one for each hemisphere)

Question 4

What are the parts of each lateral ventricle and what lobes do they correspond to?

Answer 4

• Body = Parietal lobe
• Anterior Horn = Frontal lobe
• Posterior Horn = Occipital lobe
• Inferior Horn = Temporal lobe

Question 5

What separates the lateral ventricles?

Answer 5

Septum pellucidum

Question 6

What sits on the roof of the lateral ventricles?

Answer 6

Corpus callosum

Question 7

What separates the lateral ventricles and the third ventricle?

Answer 7

Interventricular Foramen (Foramen of Munro)

Question 8

What sits on the floor of the inferior horn of the lateral ventricles?

Answer 8

Hippocampus

Question 9

What sits in the lateral wall of the lateral ventricles?

Answer 9

Caudate nucleus

Question 10

What is the shape of the third ventricle and what does it separate?

Answer 10

Slit like cleft which separates the thalami

Question 11

What sits on the roof of the third ventricle?

Answer 11

Fornix

Question 12

What separates the third ventricle from the fourth ventricle?

Answer 12

Cerebral Aqueduct (Aqueduct of Sylvius)

Question 13

What surrounds the cerebral aqueduct?

Answer 13

Midbrain

Question 14

What surrounds the fourth ventricle?

Answer 14

Hindbrain:

• Cerebellum = Posterior
• Pons and Medulla = Anterior
• Cerebellar Peduncles = Lateral

Question 15

What are the three foramina exits in the fourth ventricle to the subarachnoid space?

Answer 15

• Formamen of Luschka x2 (lateral)

- Foramen of Magendie (middle)

Question 16

Where is the choroid plexus present?

Answer 16

Throughout the ventricular system

Question 17

Where is CSF produced?

Answer 17

Choroid plexus

Question 18

What blood vessels does the choroid plexus filter?

Answer 18

Branches of the internal carotid arteries and basilar arteries

Question 19

What type of epithelium surrounds the choroid plexus?

Answer 19

Cuboidal epithelium

Question 20

How does CSF get produced?

Answer 20

1) Blood gets filtered through fenestrated capillaries

2) Components then get transported through the cuboidal epithelium and into the ventricles

Question 21

What prevent macromolecules from entering CSF?

Answer 21

Tight junctions in the cuboidal epithelium

Question 22

At what level are Lumbar punctures taken?

Answer 22

• L3/4 in adults

- L4/5 in children

Question 23

Why can the ionic composition of CSF vary from that of the plasma?

Answer 23

Because the regulation via active transport differs

Question 24

What is the purpose of a lumbar puncture?

Answer 24

To sample CSF

Question 25

What are the two types of hydrocephalus?

Answer 25

Communicating and Non-Communicating

Question 26

What is a communicating hydrocephalus?

Answer 26

When the movement of CSF into venous sinuses is impeded because of issues in absorption of CSF in the arachnoid granulations.

Question 27

What is a non-communicating hydrocephalus?

Answer 27

When there is a blockage in the ventricles (e.g. a tumour or cyst)