The cavernous sinus - contents and surrounding structures (dave's notes)

Question 1

What is found within the cavernous sinus?

Answer 1

The internal carotid artery, and VI abducens

Question 2

What is embedded in the lateral wall of the cavernous sinus?

Answer 2

3rd and 4th CNs, and O and M branches of the 5th cranial nerve

Question 3

How does the internal carotid artery enter the cranial cavity? What is its path thereafter?

Answer 3

Via the foramen lacerum. Then arches upwards and forwards, grooving the medial wall of the cavernous sinus.

Question 4

What accompanies the internal carotid artery? What branches does this give off?

Answer 4

The IC?? nerve of the sympathetic plexus. Branches to the orbit with the long ciliary nerves.

Question 5

How is the abducens nerve related to the cavernous sinus?

Answer 5

Abducens approaches the cavernous sinus from posteriorly, then crosses the lateral and anterior walls to enter the superior orbital fissure

Question 6

How is the oculomotor nerve related to the cavernous sinus? What is its course thereafter?

Answer 6

The oculomotor nerve approaches from the roof, then crosses the lateral wall inclining medially, and breaks into superior and inferior branches. It enters the superior orbital fissure medial to toehr structures, and picks up ICN??? branches

Question 7

Where is the trigeminal ganglion found?

Answer 7

The anterior part lies forward in Meckel’s cave.

Question 8

Give the divisions of the trigeminal ganglion

Answer 8

Mandibular, maxillary and ophthalmic

Question 9

What is the course of the mandibular division of the trigeminal ganglion?

Answer 9

Passes downwards to the foramen ovale

Question 10

What is the course of the maxillary division of the trigeminal ganglion?

Answer 10

Runs horizontally forward on the medial side of the lateral wall and passes through the foramen rotundum

Question 11

What does the ophthalmic division of the trigeminal ganglion divide into? What crosses some of these?

Answer 11

Three branches in the anterior part. All three branches are crossed by the oculomotor nerve.

Question 12

List the three branches of the anterior part of the trigeminal ganglion

Answer 12

Lacrimal and frontal

Nasociliary

Question 13

What is the course of the lacrimal and frontal branches of the anterior part of the trigeminal ganglion?

Answer 13

These enter through the lateral part of the superior orbital fissure

Question 14

What is the course of the nasociliary part of the trigeminal ganglion?

Answer 14

Enters through the medial part of the superior orbital fissure?

Question 15

What nerve lies lateral to the 5th CN? What is found medial to the 6th cranial nerve?

Answer 15

No nerve lies lateral to the 5th. No nerve lies medial to the 6th.

Question 16

Describe the course of the 4th cranial nerve relative to other cranial nerves

Answer 16

Runs parallel and higher with the 5th CN. Is lateral to the 3rd.

Question 17

Describe the course of the 3rd cranial nerve

Answer 17

Slopes downwards crossing medial to both the 4th and the 5th

Question 18

How does blood flow through the cavernous sinus?

Answer 18

May flow in either redirection and may communicate from one side to the other

Question 19

What veins drain to the anterior part of the cavernous sinus?

Answer 19

The superior orbital vein and the inferior orbital vein - but the latter first drains to the pterygoid plexus

Question 20

What drains to the roof of the cavernous sinus

Answer 20

The superficial middle cerebral vein

The sphenopalatine sinus

Question 21

What sinus exits the cavernous sinus?

Answer 21

The superior petrosal sinus exits the posterior wall and enters the sigmoid sinus. It also drains the ear.

Question 22

What empties the anterior compartment of the jugular foramen?

Answer 22

The inferior petrosal sinus, draining to the internal jugular vein

Question 23

What passes to the pterygoid plexus?

Answer 23

The emissary vein

Question 24

What does the inferior petrosal sinus drain?

Answer 24

The anterior compartment of the jugular foramen

Question 25

How may infection from the cavernous sinus spread? To where and via what?

Answer 25

Via the superficial middle cerebral vein, skin infection can spread to the hemispheres.

Question 26

Give two courses via which infection from the skin reaches the cavernous sinus

Answer 26

Angular vein, superior ophthalmic, cavernous sinus

Deep facial vein, pterygoid plexus, cavernous sinus

Question 27

What does cavernous sinus thrombosis cause?

Answer 27

Opthlalmoplegia.

Question 28

What thrombosis is usually fatal?

Answer 28

Retrograde thromboses to the inferior petrosal sinus