orbit cavity

Question 1

what is the orbit bounded by?

Answer 1

ethmoid & maxillary paranasal sinuses

Question 2

levator palpebrae superioris

Answer 2

lifts the superior eyelid, innervated by CN III

Question 3

orbicularis oculi

Answer 3

closes the eyelid

Question 4

conjunctiva

Answer 4

transparent mucous membrane that covers the inner surface of the eyelids and anterior surface of the eyeball, most infected (pink eye)

Question 5

lacrimal apparatus

Answer 5

keeps the surface of the eye moist, consist of glands and ducts that drain lacrimal fluid into nasal cavity

Question 6

lacrimal gland

Answer 6

tears

Question 7

lacrimal ducts

Answer 7

convey fluid to conjunctival sac

Question 8

lacrimal canaliculi

Answer 8

passage that conveys lacrimal fluid to nasal cavity

Question 9

what nerve is lacrimal production stimulated by?

Answer 9

parasympathetic CN VII (facial nerve)

Question 10

what are the 7 extra-ocular muscles of the orbit?

Answer 10

levator palpebrae superioris, 4 recti (superior, inferior, medial, lateral), 2 obliques (superior, inferior)

Question 11

common tendinous ring

Answer 11

origin of the 4 recti, surrounds the optic canal

Question 12

what is the anchor point and insertion for all extra-ocular muscles?

Answer 12

orbital bone and side of eyeball

Question 13

what is the primary action of the recti muscles?

Answer 13

elevation, depression, adduction, abduction of eyeball

Question 14

superior oblique muscle

Answer 14

posterior side, abducts and depresses pupil (look out and down) CN III

Question 15

inferior oblique

Answer 15

abducts and elevates pupil (look out and up) CN III

Question 16

superior rectus

Answer 16

elevates and adducts pupil (look up and in) CN III

Question 17

inferior rectus

Answer 17

depresses and adducts pupil (look down and in) CN III

Question 18

medial rectus

Answer 18

adducts pupil (look in) CN III

Question 19

lateral rectus

Answer 19

abducts pupil (look out) CN VI

Question 20

general sensory

Answer 20

CN V I nerves, skin of eyelid

Question 21

special sensory

Answer 21

CN II for vision

Question 22

branchial motor

Answer 22

CN VII to orbicularis oculi (closure of eyelids)

Question 23

somatic motor

Answer 23

CN III to levator palpebrae superioris, superior rectus, inferior rectus, medial rectus, and inferior oblique muscles
CN IV to superior oblique
CN VI to lateral rectus

Question 24

what arterial blood supply does the orbit receive?

Answer 24

ophthalmic artery off internal carotid artery

Question 25

the blockage of what artery results in instant blindness?

Answer 25

central retinal artery