Nervous System Part 3 - Meninges and Ventricles

Question 1

what are minenges?

Answer 1

the protective layers surrounding the brain

Question 2

what are ventricles of the brain?

Answer 2

areas of the brain that produce cerebral spinal fluid

Question 3

what are the three layers of meninges surrounding the brain?

Answer 3

outermost: dura mater
- arachnoid mater
innermost: pia mater

Question 4

what does dura mater translate to?

Answer 4

tough mother

Question 5

what is the dura mater for?

Answer 5

the external layer of the meninges that is really important for protection of the brain

Question 6

what does arachnoid mater translate to?

Answer 6

spider mother

Question 7

what does pia mater translate to?

Answer 7

tender mother

Question 8

which meninge layer is attached right to the brain and the spinal cord itself?

Answer 8

pia mater

Question 9

what does arachnoid mater get its name from?

Answer 9

the little fibrous attachments that connect the arachnoid and the pia mater
- they are called trabeculae
- they look like spider webs

Question 10

what is between the arachnoid and pia mater? (in the subarachnoid space)

Answer 10

cerebral spinal fluid (CSF)

Question 11

when the dura mater goes more internally to the brain, what is usually there?

Answer 11

in the big fissures of the brain

Question 12

what follows the dura mater? why

Answer 12

the other meninges layers
- this is so that it allows cerebral spinal fluid from the subarachnoid space to get access to all the areas of the brain

Question 13

what is the cerebral spinal fluid important for?

Answer 13

protection and nourishment of brain tissue

Question 14

what do we get when we have the dura mater and the other meninges following down a fissure in the brain?

Answer 14

a dural fold (looks like the inside folds on those big sweet peppers lol)

Question 15

what happens between the two layers of the dura mater when the dural folds form?

Answer 15

a space called the ‘venous sinus’ forms between the two layers of dura mater when they separate

Question 16

what are venous sinuses for?

Answer 16

they are areas for drainage of poorly oxygenated blood around the brain (technically veins)

Question 17

where do venous sinuses form?

Answer 17

within the dural folds

Question 18

what does the venous sinuses collect?

Answer 18

poorly oxygenated blood from around the brain and they bring it back towards the heart just like any other good vein

Question 19

in a few spaces of our venous sinuses, what will we get?

Answer 19

a few spots will get outcroppings of arachnoid mater (called arachnoid granulations/villi)

Question 20

what does the outcroppings of arachnoid mater (arachnoid granulations/villi) in the venous sinuses allow?

Answer 20

this allows the subarachnoid space to send waste products and old cerebral spinal fluid into the venous system

Question 21

what are arachnoid granulations/villi?

Answer 21

the outcroppings of arachnoid mater in the venous sinuses

Question 22

what keeps the brain nice and safe from impact?

Answer 22

the cerebral spinal fluid

Question 23

what are the functions of cerebral spinal fluid?

Answer 23

1. protection
2. buoyancy (fluid helps lift the brain up so its not fully pressured onto the vertebrae)
3. a marker of the health of the nervous system

Question 24

what are the four ventricles of the brain?

Answer 24

• the two lateral ventricles
• third ventricle
• fourth ventricle

Question 25

the two lateral ventricles follow which shape?

Answer 25

the basal nuclei
- kind of a C shape from an lateral view and also the anterior view

Question 26

what are the two lateral ventricles connected by?

Answer 26

together and to the third ventricle by the interventricular foramen

Question 27

where is the third ventricle of the brain?

Answer 27

tucked into the thalamus. the thalamus surrounds it

Question 28

how is the third ventricle connected to the fourth ventricle?

Answer 28

by the aqueduct or the cerebral aqueduct

Question 29

where is cerebral spinal fluid made?

Answer 29

in all four brain ventricles

Question 30

where is choroid plexus located?

Answer 30

in the ventricles of the brain

Question 31

what is the choroid plexus?

Answer 31

some crumbly brown stuff in the ventricles of the brain

Question 32

what is the choroid plexus made of?

Answer 32

• blood capillaries
• specialized cuboid epithelial cells called ependymal cells

Question 33

what do we do when we want to make cerebral spinal fluid?

Answer 33

• plasma from the blood is going to flow through the ependymal cells
• the ependymal cells will add other substances like proteins
• and CSF comes out into the ventricles

Question 34

if we want the CSF to leave the ventricles and go into the subarachnoid space, how will they leave the ventricles?

Answer 34

through the lateral (2) or median apertures which all open into the subarachnoid space and sometimes leak into the spinal cord because the spinal cord is also surrounded by meninges and subarachnoid space

Question 35

what are the two places the CSF can go after the fourth ventricle?

Answer 35

1. the subarachnoid space
2. central canal (just flow down the fourth ventricle)

Question 36

what is the central canal?

Answer 36

a little opening in the middle of the spinal cord that runs all the way down.
- this is how we get CSF all the way down through the spinal cord for nutrients and protection more centrally in the spinal cord