Orbit

Question 1

what makes up the superior wall of orbit

Answer 1

2 sphenoid lesser wing + frontal (orbital plate)

Question 2

what makes up the medial wall of orbit

Answer 2

3 lacrimal + ethmoid + maxilla (frontal process)

Question 3

what makes up the infr wall of orbit

Answer 3

3 maxilla (orbital process) + zygomatic + palatine

Question 4

what makes up the lateral wall of orbit

Answer 4

2 sphenoid greater wing + zygomatic

Question 5

which two conjunctiva layers? what type of tissue? where do they meet? medial fold of conjunctiva near lacrimal lake is called?

Answer 5

bulbar and palpebral
stratified columnar
supr and infr fornices
plica semilunaris

Question 6

diameter of pupil controlled by which 2 muscles

Answer 6

sphincter pupillae and dilator pupillae

Question 7

tarsal plates (superior and inferior) held by what ligaments? what connects it to periosteum?

Answer 7

medial and lateral palpebral ligaments

orbital septum

Question 8

layers of the eyelid

Answer 8

5

• skin
• subcutaneous
• muscular: orbicularis oculi+levator palpebrae superioris (upper eyelid)
• tarsofacial layer: tarsal glands and plate
• palpebral conjunctiva

Question 9

trace lacrimal gland innvervation

Answer 9

superior salivatory nucleus -> VE-para/pre -> greater petrosal n of CNVII [para/pre, SS from soft palate] + deep petrosal (sym/post, from tympanic plexus (associated w CNIX) = Vidian n -> pterygoid canal -> PPG (para/pre synapses) -> pterygopalatine n -> V2 -> zygomatic n -> communicating branch -> lacrimal n -> lacrimal gland

Question 10

trace tear drainage

Answer 10

lacrimal gland -> lacrimal duct -> supr/infr fornix -> lacrimal punctum of lacrimal paiila -> lacrimal canaliculi -> lacrimal sac -> nasolacrimal duct -> infr nasal meatus of nasal cavity

Question 11

bones of orbit lined with __? the ___ sheath envelop eyeball from optic n to corneoscleral junction, which is pierced and reflects onto the extraocular muscles as __ sheath. the optic n is covered by ___? expansions of fascial sheath @ medial + lateral rectus are ___ and ___ ____ ligaments, which blends w fasica of infr rectus and oblique muscles as ____ ligament, which prevents

Answer 11

periorbita
fascial (bulbar sheath, Tenon's capsule)
tubular muscle
all 3 meningial layers
medial + lateral check ligament
suspensory
limits depression

Question 12

common tendinous ring (annulus of Zinn) is origin of?

Answer 12

SR IR LR MR

Question 13

orbital axis and optical axis differ by __ degree, which axis of rotation for which mov’t?

Answer 13

23

anteroposterior: intorsion/extorsion
horizontal: elevation/depression
vertical: abduction/adduction

Question 14

muscles involved in

1) elevation
2) depression
3) abduction
4) adduction
5) lateral rotation
6) medial rotation
7) elevation of eyelid

Answer 14

1) SR IO
2) IR SO
3) LR IO SO
4) MR SR IR
5) IO IR
6) SO SR
7) LPS

Question 15

optic n enters through ___ with ___, its funct comp is? blood supply?

Answer 15

optic canal, ophthalmic artery, SS, central artery of retina

Question 16

oculomotor n enters through ___ and gives off? innervates? funct comp?

Answer 16

superior orbital fissure, supr and infr branch, innervates all extraocular but supr oblique and lat rectus

SE SA
VE-para/pre VA from Edinger-Westphal -> INFR div of CNIII -> ciliary ganglion (motor root) -> VE-para/post course thru SHORTciliary n -> innervate ciliary body and sphincter/constrictor pupillae muscles.
gets VE-sym/post from internal carotid n plexus with SUPR div of CNIII to innervate superior tarsal muscle (Muller’s, SMC)

Question 17

trochlear n enters through __ and innervates? funct comp?

Answer 17

supr orb fissure, supr oblique muscle, SE SA

Question 18

branches of the ophthalmic n (CN V1), further branches? fucnt comp? courses through?

Answer 18

1) frontal -> supraorbital (lateral, bigger) + supratrochlear (medial, smaller)
2) lacrimal
3) nasociliary -> long ciliary + posterior/anterior ethmoidal (ant ends up as external nasal). nasociliary ENDS UP as intratrochlear

SA except long ciliary of nasociliary, which has VE-sym/post for dilator pupillae muscle

superior orbital fissure

Question 19

abducent n enters through? innervates? funct comp

Answer 19

superior orbital fissure, lateral rectus

SE SA

Question 20

what branches from ICA

Answer 20

ONLY ophthalmic

Question 21

branches of ophthalmic art

Answer 21

9
central art of retina
lacrimal
dorsal nasal
ant ethmoidal
post ethmoidal
long posterior ciliary
short posterior ciliary
supraorbital
supratrochlear

Question 22

venous drainage of orbit

Answer 22

corresponding opthalmic art branches -> supr/infr ophthalmic veins
infr ophthalmic drains into supr AND pterygoid venous plexus -> deep facial vein
supr ophthalmic drains into cavernous sinus

Question 23

contents of fibrous/outer eye layer

Answer 23

cornea (innervated by ciliary nerves) and sclera

Question 24

contents of vascular/pigmented/ middle layer

Answer 24

iris: contains sphincter (parasym) and dilator (sym) pupillae
ciliary body: muscular attachment pt for lens, ciliary muscle (SMC), parasym for accommodation
choroid: nourishes retina

Question 25

macula lutea contains what

Answer 25

the fovea centralis

Question 26

anterior chamber separated from post chamber by

Answer 26

iris

Question 27

innervation of

1) LPS
2) SR
3) IR
4) MR
5) LR
6) SO
7) IO

Answer 27

1) supr div of CNIII (supr tarsal by VE-sympost from ICP)
2) supr div of CNIII
3) infr div of CNIII
4) infr div of CNIII
5) CNVI
6) CNIV
7) infr div of CNIII

Question 28

roots and funct comp of ciliary ganglion

Answer 28

motor: para/pre (CNIII infr division)
sensory: SA, joins nasociliary of CNV1
sympathetic: sym/post from superior cervical ganglion via carotid plexus

short ciliary n -> para/post innervate ciliary body + sphincter pupillae, sym/post innervate blood vessel