HUBS 191 Lecture 21

Question 1

what are the meninges

Answer 1

protective coverings for the brain

Question 2

what is the order of the meninges

Answer 2

dura mater, arachnoid, pia mater

Question 3

what are the two layers of the dura mater

Answer 3

the inner (periosteal) and outer (meningeal)

Question 4

what is the dura mater

Answer 4

the outermost layer of the meninges - it is dense and fibrous meaning it’s very tough

Question 5

what do the spaces between the layers of the dura mater form

Answer 5

the venous sinuses - only in the dural folds

Question 6

what are the venous sinuses

Answer 6

collection veins that collect venous blood from the brain and ‘old’ CSF after it has cycled thorough the ventricular system

Question 7

what are dural folds

Answer 7

folds formed from the inner layer of the dura meter that seperate the major divisions of the brain and provide stability for the brain within the cranium

Question 8

what are the three dural folds

Answer 8

the falx cerebri
the falx cerebelli
tentorium cerebelli

Question 9

what does the falx cerebri seperate

Answer 9

the cerebral hemispheres in the median plane

Question 10

what does the the falx cerebelli seperate

Answer 10

the cerebellar hemispheres

Question 11

what does the tentorium cerebelli seperate

Answer 11

the cerebrum from the cerebellum in the horizontal plane

Question 12

what is the subarachnoid space

Answer 12

the space between the arachnoid and the Pia mater filled with CSF, blood vessels and arachnoid trabeculae

Question 13

what are arachnoid granulations

Answer 13

parts of the arachnoid that perforate the inner layer of the dura mater. they transport ‘old’ CSF from subarachnoid space into venous sinus.

Question 14

what is the Pia mater

Answer 14

the inner layer of the meninges that is transparent and delicate. blood vessels in the arachnoid space sit on top of the Pia mater. they adhere to the brain and follow geri and extend into sulci

Question 15

what is the ventricular system

Answer 15

a network of interconnected spaces (ventricles) within the brain that are filled with CSF

Question 16

what is the ventricular system lines with

Answer 16

ependymal cells with circulate CSF using waving cilia

Question 17

what produces CSF

Answer 17

the choroid plexus

Question 18

what composes the ventricular system

Answer 18

two lateral ventricles, the third ventricle, the cerebral aqueduct, the fourth ventricle and the central canal

Question 19

how many lateral ventricles do you have

Answer 19

2 - one in each cerebral hemisphere

Question 20

where is the third ventricle located

Answer 20

in the diencephalon

Question 21

where is the cerebral aqueduct located

Answer 21

in the mid brain - it connects the third and fourth ventricles

Question 22

where is the fourth ventricle located

Answer 22

at the level of the cerebellum

Question 23

epithelial cells of the _________ make up the blood/CSF barrier which keeps blood away from the ____

Answer 23

choroid plexus - CSF

Question 24

where is the choroid plexus located

Answer 24

in the lateral ventricles (mostly)

Question 25

what does the CSF provide other than nutrients and waste for the CNS

Answer 25

shock absorption and cushioning (it has a relatively high pressure so it can act as a shock damper)

Question 26

where does CSF flow from and to

Answer 26

it starts in the lateral ventricles then the third ventricle, the cerebral aqueduct, the fourth ventricle, the subarachnoid space. within the subarachnoid space it flows around the brain and spinal cord. it exits through granulation into the venous sinus

Question 27

what is CSF

Answer 27

it is an ultra filtrate of plasma that provides protection for the brain, provides nourishment, removes metabolic waste, removes foreign particles, circulates hormones from the blood

Question 28

the CSF is normally considered sterile when can it contain microbes

Answer 28

during infection