Meninges and Blood Supply to the Brain

Question 1

Describe the pia mater (thickness, location, topography).

Answer 1

a simple squamous epithelium lying on the surface of the brain that follows all of the gyri and sulci

Question 2

Describe the arachnoid mater (thickness, location, topography).

Answer 2

A filmy, opaque layer that follows all of the gyri and sulci. Has an outer and an inner portion.
Outer: membranous, forms a sheet next to the dura mater
Inner: trabecular, forms bridges to the pia mater

Question 3

Describe the dura mater (thickness, location, topography).

Answer 3

a tough, fibrous outermost layer of the meninges that is not connected to the arachnoid mater beneath it but is normally in close apposition to it

Question 4

Describe the subarachnoid space.

Answer 4

It is the space between the membranous portion of the arachnoid, and the pia mater. Normally filled with CSF.

Question 5

Describe the subdural space.

Answer 5

between the dura mater and the outer membranous portion of the arachnoid mater

Question 6

Describe the epidural space.

Answer 6

external to the dura mater, between the dura mater and the periosteum of the skull

Question 7

What nerves innervate the dura mater of the anterior cranial fossa?

Answer 7

anterior & posterior ethmoidal branches of the ophthalmic nerve
meningeal branches of the maxillary & mandibular nerves

Question 8

What nerves innervate the dura mater of the middle cranial fossa?

Answer 8

meningeal branches of the maxillary & mandibular nerves

tentorial nerve

Question 9

What nerves innervate the dura mater of the posterior cranial fossa?

Answer 9

tentorial nerve

branches of the second & third cervical spinal nerves

Question 10

Name the 4 projections of the dura mater.

Answer 10

1. falx cerebri
2. falx cerebelli
3. tentorium cerebelli
4. diaphragma sella

Question 11

What does the falx cerebri lie between?

Answer 11

the 2 cerebral hemispheres

Question 12

What is contained in the superior surface of the falx cerebri?

Answer 12

superior surface splits to contain the superior sagittal sinus

Question 13

What is contained in the inferior surface of the falx cerebri?

Answer 13

inferior surface splits to contain the inferior sagittal sinus

Question 14

What are the anterior, superior, and inferior/posterior attachments of the falx cerebri?

Answer 14

anteriorly: crista galli
superiorly: superior sagittal sinus
inferiorly/posteriorly: tentorium cerebelli

Question 15

What does the falx cerebelli lie between?

Answer 15

the 2 cerebellar hemispheres

Question 16

What is contained in the posterior border of the falx cerebelli?

Answer 16

posterior border splits to form the occipital sinus

Question 17

What is the falx cerebelli attached to?

Answer 17

it is attached to the posterior and inferior parts of the tentorium cerebelli

Question 18

What does the tentorium cerebelli support?

Answer 18

the occipital lobes

Question 19

What is contained in the posterior and lateral borders of the tentorium cerebelli?

Answer 19

the posterior and lateral borders split to contain the transverse sinus

Question 20

What is contained in the anterior border of the tentorium cerebelli?

Answer 20

anterior border splits to contain the superior petrosal sinus

Question 21

What is clinically significant about the free border (internal border) of the tentorium cerebelli?

Answer 21

The free border is called the “incisure of the tentorium cerebelli.” In cases of cerebral edema or other “mass lesions”, the swollen brain presses against the oculomotor nerve as it passes along the incisure producing the symptoms of oculomotor nerve palsy.

Question 22

What is the diaphragma sella?

Answer 22

a circular, horizontal fold of dura mater that forms a roof above the hypophyseal fossa of the sella turcica, covering the pituitary gland

Question 23

Through what aperture does the hypophyseal stalk pass?

Answer 23

passes through the central aperture of the diaphragma sella

Question 24

What are the 9 sinuses of the brain?

Answer 24

1. superior sagittal sinus
2. inferior sagittal sinus
3. straight sinus
4. transverse sinus
5. sigmoid sinus
6. cavernous sinuses
7. superior petrosal sinus
8. inferior petrosal sinus
9. occipital sinus

Question 25

Through what opening do the vertebral arteries enter the posterior cranial fossa?

Answer 25

foramen magnum

Question 26

The right and left vertebral arteries fuse to form the _____

Answer 26

basilar artery

Question 27

The basilar artery splits to form the _____

Answer 27

right and left posterior cerebral arteries

Question 28

What arteries connect the anterior and posterior circulations of the arterial supply of the brain?

Answer 28

posterior communicating arteries

Question 29

What are the final three branches of the internal carotid artery?

Answer 29

middle cerebral artery anterior cerebral artery posterior communicating artery

Question 30

What 4 branches arise off of the internal carotid artery before its final 3 branches?

Answer 30

inferior hypophyseal artery superior hypophyseal artery ophthalmic artery anterior choroidal artery

Question 31

What arteries make up the Circle of Willis?

Answer 31

``` anterior cerebral middle cerebral posterior communicating anterior communicating posterior cerebral a small portion of the internal carotid ```