Orbit 1

Question 1

List the boundaries of the orbit .

Answer 1

supra orbital margin : frontal bone

infra orbital margin : maxilla , zygomatic

medial margin: maxilla and frontal bones

lateral margin zygomatic and frontal bone .

Question 2

list and label all fissures and foramens in the eye orbit .

Answer 2

supra orbital fissure

infra orbital fissure

optic canal

infra-orbital foramen

Question 3

what structures go through the superior orbital fissure ?

Answer 3

lateral part:

• ophthalmic artery
• superior ophthalmic vein
• lacrimal N.
• frontal N.
• trochlear N.

Middle part:

• oculomotor N. (3rd cranial nerve)
• abducent N. (6th cranial nerve )

medial part:

-inferior ophthalmic vein

Question 4

list the contents of the orbit .

Answer 4

1. ) eye ball
2. ) muscles of orbit (extra ocular and intra ocular )
3. ) nerves : optic nerve , oculomotor nerve with ciliary ganglion , trochlear nerve , abducent nerve branches of ophthalmic nerve
4. ) vessels : ophthalmic artery , superior and inferior ophthalmic veins
5. )lacrimal gland
6. )orbital fat

Question 5

how many muscles of orbit are voluntary and how many are involuntary?

Answer 5

7 voluntary and 3 involuntary

Question 6

list all 7 voluntary in the orbit .

Answer 6

superior rectus 
inferior rectus 
lateral rectus 
medial rectus 
levator palpabrae superioris 
superior oblique 
inferior oblique

Question 7

what are the 3 involuntary muscles of the orbit ?

Answer 7

superior tarsal : elevates the upper eyelid

inferior tarsal : depresses lower eyelid

orbitalis

Question 8

formula :

Answer 8

(LR6 SO4)3, ALL muscles are supplied by 3rd cranial nevre which is the oculomotor nerve except for the lateral rectus which is supplied by the 6th cranial nerve ( abducent ) and the superior oblique which is supplied by the 4th cranial nerve which is the trecheolar