eyelid physiology (opb352)

Question 1

what are eyelids function?

Answer 1

mechanical defence

shut down the stimuli when we asleep

prevent eyes from drying (xerosis)

spreading tear film

helps eye get o2 and nutrition while wearing contactlenses

Question 2

Give examples of assisting structure of eyelids

Answer 2

cilia, brow, palpebral aperture, lid margin

Question 3

what are the duration growth of cilia

Answer 3

3-5 months

Question 4

how can we make cilia grow faster?

Answer 4

remove it

Question 5

what are the function of cilia?

Answer 5

protect the eyes, receive stimulant which result in reflex, reduce evaoration of tear

Question 6

what stimulation is the reflex in blinking?

Answer 6

tactile (touch)

Question 7

what are the flaws of cilia called?

Answer 7

trichiasis

Question 8

what affect to brow muscle if we have ptosis

Answer 8

frontalis contract to elevate

Question 9

what is the average length of palpebral aperture?

Answer 9

29mm

Question 10

what is the average width of palpebral aperture?

Answer 10

9.5

Question 11

how the upper lid is sitting on our eyes?

Answer 11

overlap cornea 1mm

Question 12

how the lower lid is sitting on our eyes?

Answer 12

just right at inferior limbus

Question 13

what are the most lateral and medial of the eye?

Answer 13

lateral canthus and medial canthus

Question 14

what structure is in between caruncle and sclera?

Answer 14

plica semilunaris

Question 15

what happen with palpebral aperature when getting older?

Answer 15

width decrease

Question 16

what happen with palpebral aperature when downgaze

Answer 16

smaller

Question 17

what complexity can happen with palpebral aperature?

Answer 17

ptosis, exophthalmus, endophthalmus

Question 18

what forward protusion of the globe is called?

Answer 18

exophthalmus

Question 19

what backward position of the globe is called?

Answer 19

endophthalmus

Question 20

how can we know if that person have endolphthalmus/exophthalmus?

Answer 20

notice how lower eyelid is placed according to the limbus

Question 21

what complication can follow exophthalmus

Answer 21

tear film is not smooth

Question 22

what keep lid margin close apposition to the globe

Answer 22

tarsal plate, medial and lateral palpebral ligament, muscle of riola

Question 23

what is the position of lid wiper relatively to marx’s line?

Answer 23

posterior

Question 24

what is the pressure of eyelids to the globe

Answer 24

8.0 +- 3.4 mmHg

Question 25

width region of contact between lid margin and ocular surface?

Answer 25

0.6 +- 0.16

Question 26

what is the difference between trachiasis and entropian?

Answer 26

trachiasis is cilia grow abnormally. entropian is lid margin fold inward

Question 27

what is ectropian?

Answer 27

lid margin turnaway from the eye

Question 28

what indicate lid wiper epitheliopathy?

Answer 28

staining in lid wiper region

Question 29

what stain is used to indicate lid wiper epitheliopathy

Answer 29

rose bengal and lissamine green

Question 30

why levator muscle and OO cannot contract at the same time

Answer 30

reciprocal inhibition

Question 31

how does upper lid move when closing the eyes

Answer 31

downward slightly nasal

Question 32

how does lower lid move when closing the eye

Answer 32

nasally

Question 33

eye clsoing phase is faster or slower than opening phase

Answer 33

faster

Question 34

what is the duration of opening + closing eye lids

Answer 34

0.25 sec

Question 35

how eye rotate when blink normally

Answer 35

slight down and inward

Question 36

how eye rotate when force blink

Answer 36

large up and out

Question 37

what is bell's phenomenon

Answer 37

when the eye move largely upward and outward

Question 38

what nerve is damaged causing bell's eye palsy

Answer 38

7th cranial nerve

Question 39

bell's eye palsy occur in what muscle

Answer 39

orbicularis oculi

Question 40

what is the effect of bell's eye palsy

Answer 40

dry eye (can't close the eye properly)

Question 41

how do eyes move when blinking

Answer 41

(up&out) or (in&down) + retraction (moving backward)