GA: Dural Sinuses + Meninges

Question 1

What are the cranial meninges?

Answer 1

Sup. –> Deep

Dura mater, Arachnoid Mater, Pia mater

They are dense connective tissue layers that reparate the soft tissue of the brain from the bones of the cranium. They contain + circulate cerebral spinal fluid. They are supplied by the middle meningeal artery.

Question 2

Describe dura mater…

Answer 2

Strongest of meninges

2 layers: Periosteal (more superficial) + Meningeal

In some places there is a sinus inbetween these 2 layers

Question 3

The arachnoid (spider) mater has which spaces?

Answer 3

Subdural/Subarachnoid spaces

Question 4

Describe the pia mater…

Answer 4

It is adhered to the brain (delicate)

Question 5

What are the 4 cranial dural septa?

Answer 5

1. Falx cerebri
2. Tentorium cerebelli
3. Falx cerebelli
4. Diaphragma sellae

*These are tenting formations from the meningeal layer of dura mater that separate the brain. In these septa are dural venous sinuses*

Question 6

What are the dural venous sinuses?

Answer 6

Superior and inferior sagittal sinuses, straight sinus, sigmoid sinus, and transverse sinus

Question 7

What is cool about the facial vein?

Answer 7

It can drain inferiorly (down face) or posteriorly through the orbits into the cavernous sinus

Question 8

Can you label these?

Answer 8

1. Superior sagittal sinus 2. Inferior Sagittal sinus
2. Straight sinus 4. Confluence of the sinuses
3. Transverse sinus 6. Sigmoid sinus
4. Cavernous sinus 8. Anterior intercavernous sinus
5. Posterior Intercavernous Sinus 10. Sphenoparietal sinus
6. Superior petrosal sinus 12. Inferior Petrosal Sinus

*all drain into internal jugular V.*

Question 9

Where should all blood from the dural venous sinuses drain?

Answer 9

Cavernous sinus

Question 10

What happens if you have a cavernous sinus thrombosis?

Answer 10

Since the abducens N. = most out in the open it is most susceptible

Fever, periorbital edema (swelling around eye, no orbital venous drainage), decreased visual acuity

Question 11

What structures are found in the cavernous sinus?

Answer 11

Pituitary gland, Internal Carotid A., Ophthalmic N., Maxillary N. Oculomotor N, Trochlear N., Abducent N.

*directly behind eyes*

Question 12

What is the function of cerebrospinal fluid?

Answer 12

Buoyancy

Protection

Environental stability

Question 13

Where does CSF drain into?

Answer 13

Dural venous sinuses –> ultimately joining venous blood

Question 14

What vein drains the bulk of the head + neck?

Answer 14

Internal Jugular V.

Question 15

What is the point of yawning?

Answer 15

A reflex triggered by venous stagnation.

Question 16

What is the point of the pterygoid plexus (veins of head + neck)?

Answer 16

Acts as a peripheral pump to return venous flow every time the mouth is opened.

Question 17

Veins