4 - Meninges & Dural Venous Sinuses

Question 1

Describe the payer of dura mater and how it related to spinal nerves?

Answer 1

Dura mater is over the dorsal root ganglia and comes to the spinal nerve where it interdigitates with the outer covering of the nerves.

Question 2

How does epidural anesthesia work?

Answer 2

It runs along the dura until it reaches the spinal nerve distally.

Question 3

Where does spinal anesthesia have its affect? What is an important thing to considering when administering spinal anesthesia?

Answer 3

It is in the CSF of the subarachnoid space.

Keep them sitting up so the substances doesn’t get to the brain.

Question 4

What are the air-filled sinuses of the brain?

Answer 4

Maxillary sinus, frontal sinus, and sphenoid sinus.

Question 5

Where are dural venous sinuses located?

Answer 5

Blood-filled sinuses between the periosteal and meningeal layers of the dura mater.

Question 6

What is the function of the dorsal venous sinuses?

Answer 6

Bring venous blood back to CV.

CSF from the arachnoid granulations will also flow into the dorsal venous sinuses.

Question 7

What vessel is deep to the pterion? What is this vessel a branch of and what is its path?

Answer 7

The middle meningeal artery, a branch of the maxillary artery, heads superiorly through the foramen spinosum.

Question 8

What are the two classification of veins found in the head?

Answer 8

Emissary veins (diploid) - work their way through the skull and connects superficial to deep structures and drain some of the sinuses.

Cerebral veins (bridging veins) - delicate and go through the dura mater and go into the dural venous sinuses.

Question 9

What is the clinical significance of cerebral (bridging) veins?

Answer 9

They are delicate and go through the dura mater.

They can be torn during car accidents causing ripping in the subarachnoid space. Bleeding here will compress the brain and pressure will build.

Question 10

What are leptomeninges? What is leptomeningitis?

Answer 10

The pia and arachnoid mater.

Infection of the CSF, which is in between the pia and arachnoid mater.

Question 11

What nerve innervates the dura mater? Describe the distribution?

Answer 11

The trigeminal nerve.

V1 goes forward to innervate the orbit and back to innervate the orbit.

V2 lower eyelid and upper lip

V3 lower lip and jaw

Question 12

What are the three parts of the temporal bone?

Answer 12

Squamous (high), tympanic part (around the eardrum), and the petrous (hard) part.

Question 13

What veins feed into the cavernous sinus?

Answer 13

The superior opthalmic vein and the superior petrosal sinus.

The superior opthalmic connects to the angular and superficial veins at the superficial parts of the face.

Question 14

What vessels are at the edges of the falx cerebri?

Answer 14

Superior and inferior saggital sinuses.

The straight sinus connects to the superior saggital sinus and transverse sinuses at the confluence of sinus.

Question 15

What cranial nerves go through the jugular foreamen?

Answer 15

CN 9, 10, and 11.

Question 16

What does the angular vein turn into? At what point does this occur?

Answer 16

The angular vein becomes the facial vein at the bottom of the orbital rim.

Question 17

What is connected to the facial vein and leads to the cavernous sinus?

Answer 17

The pterygoid venous plexus.

Question 18

What vein is superficial to the SCM in the neck? What vein is deep to it?

Answer 18

External jugular vein is superficial to the SCM.

Internal jugular vein is deep to it.

Question 19

What are the tributaries of the facial vein?

Answer 19

1. Angular: supraorbital, supratrochlear, external nasal
2. Superior labial
3. Deep facial
4. Inferior Labial
5. Tonsillar
6. Submental
7. Submandibular

Question 20

What tributaries of the facial vein are in the danger zone of the face? Why is this region called the danger zone?

Answer 20

Angular: supraorbital

Superior Labial

Deep facial

Inferior labial

Infections here go directly back to the cavernous sinus

Question 21

What are the superficial venous connections to the cavernous sinus?

Answer 21

The superior opthalmic (from angular) and the inferior opthalmic. veins.

Question 22

What blood vessels and nerves are located in the cavernous sinus?

Answer 22

CN’s 3, 4, V1, V2, and 6

 O CAT
 O
 M

Oculomotor nerve 
Trochlear Nerve 
Opthalmic branch of trigeminal nerve 
Maxillary branch of trigeminal 
Carotid (internal) artery 
Abducens 
Trochlear nerve

Question 23

What other structures (besides artery and nerves) are located in the cavernous sinus?

Answer 23

The pituitary and the optic chiasm.

Question 24

What is an early warning sign of a blood clot in the cavernous sinus? What happens if it worsens?

Answer 24

Clot will contrict down on itself and compress CN 6 (abducent n), causing double vision.

Next it will compress CN 3 (oculomotor) and it will be difficult to open eyes; eyeball pinned down and out.

CN 4 next.

Then V1 and V2 causing stabbing pain in corresponding dermatomes.

Question 25

What bone meet at the pterion?

Answer 25

The frontal, parietal, temporal, and sphenoid bones.

Question 26

What causes a lensticular hematoma?

Answer 26

Rupture of the middle meningeal artery, which causes an epidural bleed that dissects the periosteal layer from the skull itself until it reaches a suture.

Question 27

What can occur if cerebral arteries tear and bleed into the subarachnoid space.

Answer 27

The build up of pressure from the blood can cause the brain to herniate down through the foramen magnum (central).

Question 28

What happens if bridging veins tear?

Answer 28

Blood will flow into the epidural area but will be low pressure and the hematoma will be smaller than seen with arterial bleeds.