Dural venous sinuses (48-59)

Question 1

Which stuctures lie within the cavernous sinus?;

Answer 1

6 structures (5 nerves and 1 artery). Occulomotor (CNIII), Trochlear (CNIV), opthalmic branch of trigeminal nerve (CNV1), Maxillary branch of trigeminal nerve (CNV2), Abducens nerve (CNVI), Internal carotid artery

Question 2

What are the dural folds which separate parts of the brain? Attachements?;

Answer 2

Flax cerbri (separates right and left hemisphere - anteriorly attaches to crista galli of ethmoid bone), Tentorium cerebelli (separates cerebrum and cerebellum - posteriorly attaches to clenoid process along transverse sinus on occipital bone)

Question 3

Name the paired dural venous sinuses;

Answer 3

1. Caveronous sinus’ 2. Superior Pterous sinus’ 3. Inferior Pterous sinus’ 4. Transvere sinus’ 5. Sigmoid sinus’

Question 4

Name the unpaired dural venous sinuses;

Answer 4

1. Superior sagittal sinus’ 2. Inferior sagittal sinus’ 3. Confluence of sinuses’ 4. Straight sinus’

Question 5

Where do the dural sinuses drain into?;

Answer 5

Internal jugular vein

Question 6

What bones make up the orbit?;

Answer 6

Superiorly - frontal bone. Medially - maxilla, lacrimal bone, ethmoid bone, Palatine bone. Inferiorly - Maxilla (medially) and zygomatic bone (laterally). Laterally - Zygomatic bone. Posteriorly (back) - sphenoid bone.

Question 7

What structures are at risk during flexible endoscopic sinus surgery (FESS)?;

Answer 7

Structures within/nearby the orbit - lacrimal duct, optic nerve, orbita; muscles, ehtmoid artery, the brain

Question 8

Name the structures that pass through the optic canal;

Answer 8

Optic nerve, Opthalmic artery, central retinal artery and vein, sympathetic nerves, meninges, CSF

Question 9

What does the opthalmic artery supply?;

Answer 9

Extra-occular muscles of the eye, lacrimal apparatus, skin & soft tissue around eye

Question 10

How does the opthalmic division of the trigeminal nerve exit the skull?;

Answer 10

Through the superior orbital fissure

Question 11

Which structures exit through the superior orbital fissure?;

Answer 11

Occulomotor nerve (CNIII), Trochclear nerve (CNIV), Opthalmic branch of trigeminal nerve (CNV1), Abducens nerve (CNVI), sympathetic nerves, superior & inferior opthalmic veins

Question 12

Name the branches of the opthalmic division of the trigeminal nerve;

Answer 12

1. Frontal nerve (further divides into supraorbital and infraorbital nerves), 2. Lacrimal nerve, 3. Nasocillary nerve. (All sensory branches)