The Orbit and Eye

Question 1

Conjunctiva

Answer 1

Palpebral conjunctiva, bulbar conjunctiva, conjunctival sac, fornices

Question 2

Palpebral conjunctiva

Answer 2

membrane lining inner eyelid

Question 3

Bulbar conjunctiva

Answer 3

membrane lining surface of eye

Question 4

conjunctival sac

Answer 4

potential space between the palpebral and bulbar conjunctiva

Question 5

fornices

Answer 5

conjunctival reflections from eyelid to eye

Question 6

Eyelid

Answer 6

superior and inferior tarsi, superior tarsal m. , tarsal glands, eyelashes

Question 7

Superior and inferior tarsi

Answer 7

support eyelid, dense CT

Question 8

Superior tarsal m.

Answer 8

maintains elevation of upper eyelid, sympathetic innervation

Question 9

Tarsal glands

Answer 9

with tarsi, produce lipid solution to lubricate corners of eye and form barrier

Question 10

Eyelashes

Answer 10

prevent objects from entering eye by causing reflexive and spontaneous blinking

Question 11

tarsal (meibomian) glands

Answer 11

with tarsi, produce lipid solution to lubricate corners of eye and form barrier

Question 12

Gland of Mll

Answer 12

sweat gland, secrete lipid to reduce evaporation

Question 13

Gland of zeis (ciliary glands)

Answer 13

sabaceous/oil gland associated with eyelash

Question 14

Innervation to lacrimal gland

Answer 14

Sensory= lacrimal branch of CN V1
Lacrimal fluid production= parasymppathetic fibers of CN VII
Vasoconstriction= postsynaptic sympathetics from superior cervical ganglion to internal carotid plexus

Question 15

Orbital axes

Answer 15

diverge at approximately 45

Question 16

Optical axes

Answer 16

for the 2 eyeballs are parallel; in anatomical position, run directly anteriorly

Question 17

Levator palpebrae superioris m.

Answer 17

Inn: CN III
A: elevates the upper eyelid

Question 18

Superior rectus m.

Answer 18

Inn: CN III
Action: elevates, adducts, & medially rotates eye (intorsion)

Question 19

Inferior rectus m.

Answer 19

Inn: CN III
A: Depresses, adducts, & laterally rotates eye (extorsion)

Question 20

Lateral rectus

Answer 20

Inn: CN VI
A: abducts eye (away from nose)

Question 21

Medial rectus

Answer 21

Inn: CN III
A: adduct eye (toward nose)

Question 22

Superior oblique m.

Answer 22

Inn: CN IV
A: depresses, abducts, & medially rotates eye (intorsion)

Question 23

Inferior oblique m.

Answer 23

Inn: CN III
A: elevates, abducts, & laterally rotates eye (extorsion)

Question 24

Nerve Innervation- Opthalmic

Answer 24

CN V1
Supplies the lacrimal gland and conjunctiva (forehead and center portion of nose)
3 divisions (“NFL”):
Nasociliary n., frontal n., lacrimal n.

Question 25

Nasociliary n.

Answer 25

-Ethmoidal and infratrochlear nn.
-Long ciliary nn. (sensory and sympathetics) to posterior eye

Question 26

Frontal n.

Answer 26

Supraorbital and supratrochlear nn.

Question 27

Lacrimal n.

Answer 27

supplies sensory to lacrimal gland

Question 28

Cavernous Sinus

Answer 28

Contents:
-Internal carotid a.
-Oculomotor n. (CN III)
-Trochlear n. (CN IV)
-Opthalmic n. (CN V1)
-Maxillary n. (CN V2
-Abducens n. (CN VI)

Question 29

Fiberous layer includes

Answer 29

Sclera and cornea

Question 30

Sclera

Answer 30

Posterior 5/6
-Attachment point for intrinsic and extra-occular eye mm.
-Covered by bulbar conjnctive

Question 31

Cornea

Answer 31

Anterior 1/6
-Primary refractory medium of the eyeball- change its shape suring laser eye surgery
-Highly sensitive to touch (CN V1)
-Completely avascular- aqueous humor and lacrimal fluid

Question 32

Vascular Layer includes

Answer 32

Choroid, Ciliary body, and Iris

Question 33

Choroid

Answer 33

Pigmented, dark reddish-brown layer between the sclera and retina
-Supplied by ciliary branches of ophthalmic artery
-Vascular supply for photoreceptors (rods and cones) of retina- helps to refocus light
-Causes “red eye” reflection in flash photography

Question 34

Ciliary Body

Answer 34

Connects choroid to iris and provides attachment for lens
-Ciliary processes- secretes aqueous humor
-Smooth muscle- controls lens thickness/focus- acommodation- parasympathetic from CN III via ciliary ganglion
-Zonular fibers- contain suspensory ligaments for accomodation

Question 35

Iris

Answer 35

1. Pupillary schincter= constricts pupil (limits light)
   -Cicularly arranged fibers
   -Inn by parasympathetics from CN III via ciliary ganglion
2. Pupillary dilator= dilates pupil (increases light)
   -Radially arranged fibers
   -Inn by sympathetics from internal carotid plexus

Question 36

Retina

Answer 36

Optic:
-Neural- contains light receptive neurons
-Pigmented: absorbs/reduces scattering of light
-Non-visual: anterior continuation of pigmented layers with a layer of supporting cells

Question 37

Macula

Answer 37

of retina, the fovea centralis is a depression located in the center
-Focus light onto fovea

Question 38

Optic disc

Answer 38

Blind spot, where retinal ganglia axons leave retina