Lecture 5: Dural Sinuses, Meninges, and Vasculature

Question 1

What are the three layers of the cranial meninges from superficial to deep?

Answer 1

Dura Mater
Arachnoid Mater
Pia Mater

Question 2

What are the two layers of dura mater?

Answer 2

Periosteal Layer: attached to cranial bones

Meningeal Layer

Question 3

What is the space called between the two layers of the dura mater?

Answer 3

Dural Venous Sinuses (large blood-filled spaces)

Question 4

What are emissary veins?

Answer 4

Veins that drain the scalp into the the dural venous sinuses

Question 5

What can infections of the scalp lead to?

Answer 5

Meningitis

Question 6

What are bridging veins?

Answer 6

Veins that drain cerebral cortex into the dural venous sinuses

Question 7

What is the arachnoid composed of?

Answer 7

Arachnoid Trabeculae: Web of collagen and elastic fibers

Question 8

What is the subdural space?

Answer 8

Potential space between arachnoid and dura mater.

In theory, this space should not exist.

Question 9

What can form a subdural space?

Answer 9

1. Bleeding of Bridging Veins

2. Lumbar Punctures

Question 10

What is found in the subarachnoid space?

Answer 10

1. CSF

2. Branches of Internal Carotid Arteries

Question 11

How can aneurysms form in the subarachnoid space?

Answer 11

Low collagen can cause weaker blood vessels, which can lead to higher potential of aneurysms from the ICA branches in the subarachnoid space.

Question 12

Where is pia mater found?

Answer 12

Tightly adheres to brain and follows every contour of the brain surface

Question 13

What is the cranial dural septa?

What is their purpose?

Answer 13

Meningeal layer of Dura Mater extends as flat partitions deep into the cranial cavity.
The septa provides stabilization and support for the brain. It also separates specific parts of the brain.

Question 14

What does the falx cerebri separate?

Answer 14

The two hemispheres of the cerebrum

Question 15

What does the tentorium cerebelli separate?

Answer 15

Cerebellum from Cerebrum

Question 16

What does the falx cerebelli separate?

Answer 16

The two hemispheres of the cerebellum

Question 17

What does the diaphragma sellae cover?

Answer 17

Pituitary Gland

Question 18

What plane is the falx cerebri and falx cerebelli found in?

Answer 18

Sagittal Plane

Question 19

What plane is the tentorium cerebelli found in?

Answer 19

Transverse/Horizontal Plane

Question 20

What are the five dural venous sinuses that are found in the cranial dural septa?

Answer 20

1. Superior Sagittal Sinus
2. Inferior Sagittal Sinus
3. Straight Sinus
4. Sigmoid Sinus
5. Transverse Sinus

Question 21

What is the main artery that supplies the three layers of the cranial meninges?
Where does it branch from?

Answer 21

Middle Meningeal Artery

ECA –> Maxillary Artery –> MMA

Question 22

What are the two branches of the Middle Meningeal Artery?

Answer 22

Frontal and Parietal Branches

Question 23

What cranial nerve provides sensory afferent information to the meninges?

Answer 23

All branches of Cranial Nerve V (Trigeminal Nerve)

Question 24

What causes an epidural hematoma?

What does it look like on an x-ray?

Answer 24

Ruptured Middle Meningeal Artery - can be caused if hit at the pterion
Lens shaped hematoma on side of brain

Question 25

What is a pterion?

Answer 25

Point where temporal bone, parietal bone, sphenoid bone, and frontal bone meet

Question 26

What causes a subdural hematoma?

What does it look like on an x-ray?

Answer 26

Bleeding of bridging veins most commonly seen in babies and the elderly
Crescent shaped hematoma on side of brain

Question 27

What causes a subarachnoid hematoma?

What does it look like on an x-ray?

Answer 27

Ruptured aneurysm from cerebral arteries mostly in post-menopausal women and people with hypertension
Spider like webs in middle of brain

Question 28

Where can the supra-orbital vein, superior ophthalmic vein, and inferior ophthalmic vein drain into?

Answer 28

1. Facial Vein

2. Dural Venous Sinuses via the orbit

Question 29

What does the Sigmoid sinus drain into?

Answer 29

Jugular Vein

Question 30

What structures are in the cavernous sinus?

Answer 30

Internal Carotid Artery
CN III (Oculomotor Nerve)
CN IV (Trochlear Nerve)
CN VI (Abducens Nerve)
CN V1 (Ophthalmic Nerve)
CN V2 (Maxillary Nerve)

Question 31

What type of blood surrounds cavernous sinus?

Answer 31

Venous Blood

Question 32

What nerve is next to the internal carotid artery in the cavernous sinus?

Answer 32

Abducens Nerve

Question 33

What are the four parts of the Internal Carotid Artery?

Answer 33

1. Cervical Part
2. Petrous Part
3. Cavernous Part.
4. Cerebral Part
   - –> Circle of Willis

Question 34

What causes a cavernous sinus thrombosis?

Answer 34

Infection of face that can spread through ophthalmic veins and reach cavernous sinus

Question 35

Where is cerebrospinal fluid (CSF) found?

Answer 35

Subarachnoid Space

Question 36

What makes CSF?

Answer 36

Choroid plexus in ventricles

More specifically, ependymal cells secrete fluid

Question 37

What is the difference between CSF and blood plasma composition?

Answer 37

CSF: Greater sodium and less potassium

*Both have similar amounts of hydrogen and calcium

Question 38

What structure drains CSF into dural venous sinuses?

Answer 38

Arachnoid Granulations

Question 39

What happens if there is a problem with pressure gradient with dural venous sinuses?

Answer 39

Hydrocephalus (brain has enlarged ventricles)