Eyelids (M1)

Question 1

location of upper eyelid

Answer 1

extend from conjunctival fornix to superior orbital rim

Question 2

location of lower eyelid

Answer 2

extend from conjunctival fornix to nasojugal and palpebromalar sulci

Question 3

location of lateral canthus

Answer 3

medial to lateral orbit rim.
lies on globe

Question 4

palpebral fissure

Answer 4

opening between UL and LL.
horizontally: about 30 mm
vertically: about 10 mm

Question 5

location of medial canthus

Answer 5

at medial orbital rim.
separated from globe by lacrimal lake

Question 6

vertical palpebral fissure equation

Answer 6

VPF = MRD-1 - MRD-2
marginal reflex distance-1 (MRD-1) : distance between corneal reflex and UL
marginal reflex distance-2 (MRD-2) : distance between corneal reflex and LL

Question 7

normal MRD1 and MRD 2 distance

Answer 7

MRD-1: 4-4.5 mm
MRD-2: >5 mm

Question 8

qualities of eyelid skin

Answer 8

folds easily, very flexible –> important for blinking.
thinnest skin in the body

Question 9

differences in eyelid and eyebrow skin

Answer 9

1. dermis is thinner in eyelid
2. dermis has less adnexal structures in eyelid
3. minimal hypodermis in orbital region and absent in tarsal region

Question 10

what is the composition and function of the tarsal plate

Answer 10

composition: dense connective tissue
function: give eyelid structure and rigidity

Question 11

location of superior tarsus

Answer 11

extends from eyelid margin to superior palpebral sulcus

Question 12

location of inferior tarsus

Answer 12

extends from eyelid margin to inferior palpebral sulcus

Question 13

tarsal plate attachments

Answer 13

medial and palpebral ligaments (aka. canthal tendons).
superior tarsus: levator aponeurosis and superior tarsal muscle (Muller’s muscle)
inferior tarsus: capsulopalpebral fascia and inferior tarsal muscle

Question 14

composition of orbital septum

Answer 14

sheet of dense connective tissue

Question 15

general location of orbital septum

Answer 15

entire rim of orbit to tarsal plate

Question 16

orbital septum UL attachments

Answer 16

becomes thickening of periosteum at superior orbital rim.
distal fibers merge with levator aponeurosis about 3-5 mm above tarsal plate

Question 17

orbital septum LL attachments

Answer 17

becomes thickening of periosteum at inferior orbital rim.
distal fibers merge with capsulopalpebral fascia several mm below tarsal plate

Question 18

function of orbital septum

Answer 18

separates eyelids and lacrimal sac from orbit to prevent infections from entering the orbit and also holds fat in place

Question 19

composition of orbicularis oculi muscle

Answer 19

skeletal muscle

Question 20

function of orbicularis oculi muscle

Answer 20

protractor of UL and LL.
contraction closes lids

Question 21

origination and insertion of orbicularis oculi muscle

Answer 21

origination: medial orbital rim (maxillary and lacrimal bones)
insertion: lateral palpebral ligament

Question 22

2 regions of the orbicularis oculi muscle

Answer 22

orbital and palpebral

Question 23

2 regions of palpebral region

Answer 23

preseptal and pretarsal

Question 23

fiber type, location, and contraction of orbital region

Answer 23

fiber: concentric
location: orbital rim to forehead, temple, and cheek
contraction: closes eyelids tightly, depresses eyebrows

Question 23

location of preseptal region

Answer 23

in front of orbital septum

Question 23

fiber type, location, and contraction of palpebral region

Answer 23

fiber: superior and inferior semilunar location: lateral palpebral ligament across eyelid to medial palpebral ligament contraction: closes eyelids gently

Question 24

location of pretarsal region

Answer 24

in front of tarsal plate

Question 24

composition of levator palpebral muscle

Answer 24

skeletal muscle

Question 24

2 areas of pretarsal region

Answer 24

riolan's muscle and horner's muscle

Question 25

antagonist of orbicularis oculi

Answer 25

levator palpebrae: innervated by CN VII - opens eye frontalis muscles: innervated by CN VII - raises brow

Question 26

function of levator palpebral muscle

Answer 26

main retractor of UL

Question 27

what is levator palpebral muscle anterior to

Answer 27

superior rectus

Question 28

antagonist of levator palpebral muscle

Answer 28

orbicularis oculi muscle

Question 29

composition of tarsal muscle (Mullers muscle)

Answer 29

smooth muscle

Question 30

function of tarsal muscle

Answer 30

accessory retractor of ULs and LLs. contraction opens eyelids

Question 31

origination and insertion of tarsal muscle UL

Answer 31

origination: levator muscle, about 10 mm above tarsus insertion: superior border of tarsus / 2-5 mm below

Question 32

origination and insertion of tarsal muscle LL

Answer 32

origination: capsulopalpebral fascia insertion: lower border of tarsus

Question 33

composition of capsulopalpebral fascia

Answer 33

connective tissue sheet

Question 34

function of capsulopalpebral fascia

Answer 34

main retractor of LLs

Question 35

capsulopalpebral fascia location

Answer 35

arise from Lockwood's ligament and sheath of IR and IO. course up to fuse with orbital septum 4-5 mm below tarsus --> forms common fascial sheet

Question 36

capsulopalpebral fascia attachments

Answer 36

lower border of tarsus, muscle fibers of orbicularis oculi, and skin

Question 37

capsulopalpebral fascia attachments to skin

Answer 37

inferior palpebral sulcus. - fold/groove 5 mm below LL margin - divides eyelid into tarsal and septal regions - less marked than superior sulcus

Question 38

where is palpebral conjunctiva

Answer 38

thin, transparent membrane that lines the underside of lids

Question 39

cells and glands in the palpebral conjunctiva

Answer 39

goblet cells accessory lacrimal glands of krause and wolfring

Question 40

3 layers of the eyelid

Answer 40

anterior lamella: - skin - orbicularis oculi middle lamella: - orbital septum - retractor muscles posterior lamella: - tarsal plate - palpebral conjunctiva

Question 41

grey line

Answer 41

divides anterior and posterior lamallae location: between meibomian gland openings and eyelashes surgical landmark for anterior border of Riolan's muscle

Question 42

location and function of eyelashes

Answer 42

location: ciliary portion function: protect eye with blink response - shield from outside

Question 43

glands in eyelid margin

Answer 43

glands of Zeis - holocrine, sebaceous - secrete sebum - lubricate eyelid margin glands of Moll - apocrine, sweat - secrete sweat - function: unknown

Question 44

lacrimal papilla/puncta

Answer 44

papilla: mound of tissue - location: lacrimal portion puncta: hole in center of papilla - beginning of nasolacrimal drainage system

Question 45

mucocutaneous junction

Answer 45

line of marx. location: ciliary and lacrimal portion of eyelid margin transition zone b/t palpebral conjunctiva and skin

Question 46

lid wiper region

Answer 46

location: ciliary and lacrimal portion of eyelid margin, posterior to mucocutaneous junction elevated strip of palpebral conjunctiva

Question 47

meibomian gland orifices

Answer 47

location: ciliary portion of eyelid margin - in a row function: secretes oils (lipids) onto skin in front of mucocutaneous junction whenever you blink

Question 48

what is the general function of the eyelid

Answer 48

protect the globe: - stimulation of sensory nerves --> contraction of orbicularis oculi - eyelid protracts to protect the globe