Lecture 20

Question 1

What are meninges?

Answer 1

3 layers of protective covering for the brain

Question 2

What are the 3 layers called?

Answer 2

Dura mater, arachnoid and pia mater

Question 3

List the five features of the dura mater.

Answer 3

1. Outer most layer of meninges
2. Dense and fibrous so very tough
3. Two layers of the dura mater- outer and inner
4. Space between the layers forms venous sinuses- only in some places
5. Inner layer forms the dural folds

Question 4

List the three features of the dural folds.

Answer 4

1. Formed from inner layer of dura mater
2. Separate major divisions of brain
3. Provides stability of the brain within cranium.

Question 5

What are the three different dural folds.

Answer 5

1. Falx cerebri
2. falx cerebelli
3. Tentorium cerebelli

Question 6

What does the tentorium cerebelli do?

Answer 6

Separates the cerebrum from the cerebellum and is in the horizontal plane

Question 7

What does the falx cerebri do?

Answer 7

Seperates cerebral hemispheres and is in the median plane

Question 8

What does the falx cerebelli do?

Answer 8

Seperates cerebellar hemispheres and is in the median plane/.

Question 9

List the three features of the venous sinus

Answer 9

1. Located where the two layer of dura mater seperate
2. collecting veins
3. they collect two things- Venous blood from the brain and “old” CSF after it has cycled through the ventricular system.

Question 10

Where does the arachnoid mater layer lie?

Answer 10

Below the dura mater

Question 11

What are the five features of the arachnoid mater?

Answer 11

1 Layer beneach the dura mater

2. Layer above the pia mater
3. Does not extend into sulci
4. Contains 2 special features- subarachnoid space and arachnoid granulations
5. contains blood vessels

Question 12

What are the features of the subarachnoid space?

Answer 12

Between the arachnoid and the pia mater and filled with cerebrospinal fluid (CSF)

Question 13

What are the special features of the arachnoid granulations?

Answer 13

Perforate the inner layer of dura mater and transport “old” CSF from subarachnoid space into venous sinus

Question 14

What are the four features of the Pia mater?

Answer 14

1. inner layer of the meninges
2. Transparent and delicate
3. blood vessels in arachnoid sit on top of pia mater
4. Adheres to brain and follows gyri and extends into sulci

Question 15

Does the spinal cord have meninges?

Answer 15

Yes

Question 16

What are the four features of the ventricular system?

Answer 16

1. Network of interconnected spaces within the brain
2. Filled with CSF which nourishes and protects the brain
3. Spaces lined with ependymal cells, which circulate the CSF (WAVING CILIA)
4. CSF is produced by the choroid plexus

Question 17

What are the lateral ventricles?

Answer 17

There are two of them one in the each cerebral hemisphere

Question 18

What is the third ventricle?

Answer 18

The lateral ventricles converge to form the third ventricle which is located in the diencephalon

Question 19

What is the cerebral aqueduct and where is it located?

Answer 19

It connects to the third ventricle and the 4th ventricle, it is located in the mid brain.

Question 20

What is the fourth ventricle and where is it located?

Answer 20

It is located at the level of cerebellum

Question 21

Where is the central canal?

Answer 21

The spinal cord is coming off the brain.

Question 22

What are the four features of the CSF

Answer 22

1. Surrounds the CNS within subarachnoid space
2. Provides support and cushion
3. Transports nutrients and waste
4. Produced by choriod plexux within the ventricles

Question 23

What is the circulation path

Answer 23

Start at lateral ventricles to 3rd ventricle, cerebral aqueduct, 4th ventricle, subarachnoid space, within the subarachnoid space it flows around the brain and spinal cord and then exits through arachnoid granulations into venous sinus.