Meninges

Question 1

Meninges

Answer 1

protective covering for the brain

Question 2

3 layers of cranial meninges and spinal cord meninges

Answer 2

• dura mater
• arachnoid
• pia mater

Question 3

Dura mater (5 features)

Answer 3

• outer-most layer of meninges
• dense and fibrous - tough
• two layers; outer and inner - mostly stuck together
• space between layers forms venous sinuses - only in some places
• inner layer forms the dural folds

Question 4

Arachnoid (5 features)

Answer 4

• layer beneath the dura mater
• layer above the pia mater
• does not extend into the sulci
• contains blood vessels (lying on top of pia mater)

Question 5

Pia mater (4 features)

Answer 5

• inner layer of the meninges
• transparent and delicate
• blood vessels in arachnoid sit on top of pia mater
• adheres to brain and follows gyri and extends into sulci

Question 6

Dura mater (2 components)

Answer 6

Dural folds

Dural venous sinus

Question 7

Arachnoid space (2 components)

Answer 7

Subarachnoid space

Arachnoid granulations

Question 8

3 dural folds

Answer 8

Falx cerebri
Falx cerebelli
Tentorium cerebelli

Question 9

Features of dural folds (3)

Answer 9

• formed inner layer of dura mater
• separate major divisions of brain
• provide stability of the brain within cranium

Question 10

Features of dural venous sinus (3)

Answer 10

• located where the two layers of dura mater separate
• collecting spaces
• collect: venous blood from the brain & ‘old’ CSF after it has cycled through the ventricular system

Question 11

Dural folds:

Falx cerebri

Answer 11

separates cerebral hemispheres

median plane

Question 12

Dural folds:

Falx cerebelli

Answer 12

separates cerebellar hemispheres

median plane

Question 13

Dural folds:

Tentorium cerebelli

Answer 13

separates the cerebrum from the cerebellum

horizontal plane

Question 14

Arachnoid space:

Subarachnoid space

Answer 14

• between the arachnoid and the pia mater

- filled with cerebrospinal fluid (CSF) - liquid gel layer that surrounds and protects the brain

Question 15

Arachnoid space:

Arachnoid granulations

Answer 15

• perforate the inner layer of dura mater

- transport ‘old’ CSF from subarachnoid space into venous sinus

Question 16

Ventricular system (4 features)

Answer 16

• Network of interconnected ‘spaces’ (ventricles) within the brain
• filled with (CSF), which nourishes and protects the brain
• spaces lined with ependymal cells, which circulate the CSF (waving cilia)
• CSF is produced by the choroid plexus

Question 17

Lateral ventricles

Answer 17

• 2
• one in each cerebral hemisphere
• C-shaped structure that follows the shape of the cerebrum

Question 18

Third ventricle

Answer 18

• 1

- located in the diencephalon

Question 19

Cerebral aqueduct

Answer 19

• 1
• connects the 3rd ventricle to the 4th ventricle
• located in the midbrain

Question 20

Fourth ventricle

Answer 20

• 1

- located at the level of the cerebellum

Question 21

CerebroSpinal Fluid (CSF) (4 features)

Answer 21

• surrounds the CNS, within subarachnoid space
• provides support and cushion
• transports nutrients and waste
• produced by choroid plexus within the ventricles

Question 22

CSF circulation path

Answer 22

starts at lateral ventricles —> 3rd ventricle —> cerebral aqueduct —> 4th ventricle —> subarachnoid space (within the subarachnoid space it flows around the brain and spinal cord) —> exits through arachnoid granulations into venous sinus