8.1 Functional Anatomy Of The Orbit, Eye And Ocular Muscles

Question 1

Describe the shape of the orbital cavity

Answer 1

Pyramidal shaped with apex pointing posteriorly and slightly medially.

Question 2

Name the openings at the back of the orbital?

Answer 2

Optic canal
Superior orbital fissure
Inferior orbital fissure

Question 3

Name some architectures around the orbital

Answer 3

Supraorbital notch
Lacrimal fossa
Whitnall’s tubercle
Infraorbital foramen

Question 4

What bones help form the orbit?

Answer 4

Frontal bone
Ethmoid bone
Lacrimal bone
Maxilla
Palatine bone 
Zygomatic bone 
Sphenoid bone

Question 5

What nerve is vulnerable in a fracture of the orbital floor?

Answer 5

Infraorbital nerve (branch of the maxillary division of the trigeminal nerve

Question 6

What structure sits in the lacrimal fossa

Answer 6

Lacrimal duct

Question 7

What structures are housed in the orbital?

Answer 7

Eyeball
Extra ocular muscles 
Lacrimal glands/apparatus
Fat
Nerves
Blood vessels

Question 8

What is the main arterial blood supply of the orbit?

Answer 8

Ophthalmic artery

Question 9

What artery does the central retinal artery branch from?

Answer 9

Ophthalmic artery

Question 10

What is the venous drainage of the orbit?

Answer 10

Ophthalmic veins (superior and inferior) drain venous blood into cavernous sinus, pterygoid plexus and facial vein

Question 11

What structures pass through the optic canal?

Answer 11

Ophthalmic artery

Optic nerve

Question 12

What nerve carries the special sensory from retina?

Answer 12

Optic nerve

Question 13

What nerve carries the general sensory from eye?

Answer 13

Ophthalmic division of the of the trigeminal nerve

Question 14

What nerve carries motor innervation to the muscles of the eye?

Answer 14

Mainly oculomotor CNIII (extraocular muscles and STM)
Trochlear (superior oblique muscle)
Abducens (lateral rectus muscle)