L-21

Question 1

What are meninges?

Answer 1

Protective coverings for the brain and spinal chord

Question 2

How many layers of meninges are there? What are they called?

Answer 2

• 3
• Dura Mater
• Arachnoid Mater
• Pia Mater

Question 3

Which meningeal layer is closest to the cranium?

Answer 3

Dura Mater

Question 4

What is Dura Mater

Answer 4

• the outermost layer of the meninges
• dense and fibrous- first line of defence if cranium is injured
• consists of two layers- outer and inner

Question 5

What are the spaces between the layers of dura mater called?

Answer 5

Venous sinuses

Question 6

What are the two special features of the dura mater?

Answer 6

• Venous sinuses

- Dura folds

Question 7

What are dural folds?

Answer 7

Sections of the inner dural layer that separate the major divisions of the brain and provide stability to the brain within the cranium

Question 8

How many dural folds are there? What are they called

Answer 8

• 3
• Falx cerebri
• Falx cerebelli
• Tentorium cerebelli

Question 9

What does the Falx Cerebri separate?

Answer 9

• right and left cerebral hemispheres

- on the median plane

Question 10

What does the Falx cerebelli separate?

Answer 10

Cerebellar hemispheres

- median plane

Question 11

What does the tentorium cerebelli separate?

Answer 11

• cerebrum from cerebellum
• horizontal plane
• one on each hemisphere?

Question 12

What are venous sinuses? What do they do?

Answer 12

Collecting veins located where dural layers separate. They collect venous blood from the brain and old CSF after it has cycled through the ventricular system

Question 13

What is Arachnoid mater?

Answer 13

• meningeal layer beneath the dural mater
• identified by spider like appearance
• does not extend into sulci
• Contains blood vessels within subarachnoid space

Question 14

WHat are the two special features of the arachnoid mater?

Answer 14

• Subarachnoid space

- Arachnoid granulations

Question 15

What is the subarachnoid space?

Answer 15

Area between the arachnoid and Pia mater that is filled with CSF

Question 16

What are arachnoid granulations?

Answer 16

Granulations that perforate the inner dural layer and act as pumps to transport old CSF from the subarachnoid space into the venous sinus

Question 17

What is Pia Mater?

Answer 17

• the innermost layer of the meninges
• transparent and delicate
• adheres to brain and follows gyro and extends into sulci
• blood vessels of the arachnoid layer sit on top

Question 18

What is the ventricular system?

Answer 18

A network of interconnected spaces (ventricles) within the brain. Filled with CSF which nourishes and protects the brain and are lined with Ependymal cells which circulate the CSF.

Question 19

How many ventricles make up the ventricular system? What are their names?

Answer 19

• 4 types, 5 ventricles
• lateral ventricles (2)
• Third ventricle (1)
• Cerebral aqueduct( 1)
• Fourth ventricle (1)

Question 20

Where are the lateral ventricles located?

Answer 20

One in each cerebral hemisphere

Question 21

Where is the third ventricle located?

Answer 21

in the diencephalon

Question 22

Where is the cerebral aqueduct located?

Answer 22

• in the midbrain

- connects third and fourth ventricles

Question 23

Where is the Forth Ventricle located?

Answer 23

• at the level of the cerebellum

- connects to central canal

Question 24

What are the roles of the CSF? (2)

Answer 24

• surround the CNS within the subarachnoid space and provide support and cushioning
• transport nutrients and waste

Question 25

Where is CSF produced?

Answer 25

By choroid plexus in Lateral ventricles

Question 26

What is the order of the flow of CSF?

Answer 26

• Starts in lateral ventricles (made in choroid plexus)
• Travels to and through third ventricle, cerebral aqueduct, fourth ventricle and enters subarachnoid space
• Flows around brain and spinal chord and exits through arachnoid granulations into venous sinuses