Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ocular physiology > EYELIDS > Flashcards

EYELIDS Flashcards

1
Q

What are the structures of the eyelid?

A

skin, muscle, fibrous layer, palpebral conjunctiva, subcutaneous layer, submuscular areolar layer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what are the portions of the eyelid?

A

orbital portion, tarsal portion, lateral canthus, medial canthus, superior palpebral furrow, caruncle, inferior palpebral furrow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is blepharochalasis?

A

orbital fat herniation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is significant about the skin (dermis) of the eyelid?

A

has no fat, unlike dermis in the rest of body. very thin and elastic, fat free.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is basal cell carcinoma related to?

A

UV light exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what part of the eyelid is more prone to cancer?

A

the inferior lid. because the eyebrow protects the superior from the sun. four times more common in lower lid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

how are benign growths distributed on lids?

A

evenly upper and lower lid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what are the muscles of the eyelid? what is their function

A

levator palpebral superioris = elevates lids. (innervated by CN III ocular motor nerve) (striated).
orbicularis occuli = close eyelid. (striated muscle). assist in spreading tears and flushing away waste products. voluntary muscle.
Mueller’s muscle fibers= assist levetor superioris in lifting lid. Modulate position of the open eyelid. expression of fear.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

absence of a fold is described as what clinically?

A

ptosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what marks the insertion of the levator papebral superioris?

A

fold of skin separating the palpebral from the orbital portion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what is the orbicularis occuli innervated by?

A

CN VII (facial)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

paralysis of orbicularis occuli innervated by CN VII leads to what condition?

A

dry eye condition and lagophthalmus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is lagophthalmus?

A

inability to close eye lids. incomplete closure of eyelid during sleep. exposure of cornea-scleral limbus. lower cornea is usually what gets dry.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

levator palpebral superioris becomes tendinous where?

A

aponeurosis of the levator.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

muller muscle (superior and inferior) or tarsal muscles is innervated by what?

A

sympathetic nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

damage to sympathetic innervation can cause what?

A

droopy lid.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is the function of the fibrous layer tarsal plate?

A

dense fibrous tissue that gives firmness and shape to eye lids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

what is the function of the submuscular areolar tissue?

A

loose connective tissue between muscle and tarsal plate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

collagen is more developed in which part of the lid upper or lower? which is everted usually?

A

collagen is more developed in upper lid. Allows upper lid to be everted.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

what are characteristics of Floppy Eyelid Syndrome?

A

flaccid upper lid, genetic abnormalities in collagen or elastin of lid. decrease tarsal elastin.

21
Q

patients with Floppy eye syndrome will experience what symptoms?

A

irritation and burning of eye. Eyelid rub against pillow while sleeping. meibomian gland dysfunction, inadequate spreading of tears. and poor apposition of eyelid to globe. associated with sleep apnea. don’t confuse with floppy iris syndrome.

22
Q

how many lashes does the upper and lower lid have?

what is the lifespan? How long does it take to be replaced when forcibly removed?

A

upper= 100-150
lower= 50-75
The lifespan is about 3-5 months
It takes 2 months to be replaced when forcibly removed.

23
Q

explain eyelid secretion.

A

Chief secretion: sebum
Oily material secreted by the meibomian glands
The sebum forms a superficial layer over the precorneal tear film which slows evaporation of the aqueous component. A hydrophobic barrier is formed to prevent tear spillage.

24
Q

what is the function of the miebomian glands?

A

secrete oil layer of tear. sebum. forms surface of tear. large sebecaus glands embedded in tarsal plates. there are 30 glands in each tarsus. pressure in the glands cause the glands to excrete.

25
Q

what are the accessory lacrimal glands called?

A

wolfrig and krause

26
Q

what is the arterial supply of the eyelid?

A

Arteries in lid anastomose – form two transverse arcades per eyelid
Arterial supply:
Facial system (from external carotid artery)
Orbital system (from internal carotid artery)

27
Q

what is the venous drainage of the eyelid?

A

superficial system (pre-tarsal) and deep system (post tarsal)

28
Q

describe lymphatics of the eye lid.

A

lymphatics are found in the eye lid and the conjunctiva.

divided into two parts superficial (pre-tarsal plexus) and Deep post-tarsal plexus)

29
Q

What happens with paralysis of CN 7?

A

the eyebrow is lower on the affected area side.

30
Q

what happens when CN 3 is affected?

A

Weak= ptosis
paralysis= complete closure of the eye
if lift the eyelid patient would see double.

31
Q

which EOM are supplied by CN3?

A 
medial rectus, inferior rectus, superior rectus, inferior oblique.
REMEMBER:
all the rest CN3. 
and
S04 
LR 6
32
Q

what muscle can try to compensate to lift lid for patient with ptosis?

A

the frontalis muscle, which lifts the eyebrow.

33
Q

what happens when there is a sympathetic paralysis of Muller’s muscle?

A

a small ptosis can occur. sympathetic paralysis is a component of horner’s syndrome. however, it can be treated with low weak dosage solution of epinephrine to fix it.

34
Q

what does the corrugator supercilli and frontalis muscle do?

A

pulls eyebrows together = frown

frontalis muscle= raises eyebrows

35
Q

what’s bell’s phenomenon?

A

The globe turns upward as the eyelids are forced closed. (protects cornea by moving it up).
Try applying force on the orbicularis muscle and ask the patient to close eyelid.

36
Q

what’s reflex blinking?

A

rapid closure movement and a response to stimuli.
Examples:
rapid object movement toward eye, touch, strong lights, loud noise, etc.

37
Q

what does a aesthesiometer do?

A

corneal reflex.

38
Q

in the contact lens wearer, what can happen to corneal reflex?

A

tactile corneal reflex is reduced.

39
Q

what is blepharospasm?

A

Muscle cannot relax.
Raises IOP (intraocular pressure). Involuntary closure of eyes. Slow, sustained closure to nonreceptive (pain) stimuli. idiopathic disorder of neuromuscular control. (effects orbicularis oculi).
Botox lasts 2-3 months or can be treated temporarily by butolinum (toxin).

40
Q

explain spontaneous blinking.

A

happens on a regular basis. Lower lid remains almost stationary
most the movement is made by the upper lid
The palpebral fissure narrows in a zipper-like motion laterally to medially.
Tear strip moves towards the puncta

rate is low or absent in infants. happens despite blindness.

41
Q

what is the spontaneous blink rate? Duration between blinks? how long is blink?

A

we blink 15 times per minute
blink= 300-400 msec
duration between blinks= 2.8 sections
obscuring visual input for more than 30 msec is detectable but for less than 3 msec not detectable.

42
Q

what is voluntary winking?

A

voluntary closure of the eye. Most people can wink with left eye freely and not right. This is related to predominance of right handedness.

43
Q

what is myokima?

A

Eyelid twitching. Aggravated by fatigue, thyrotoxicosis, and psychological stress.

44
Q

what is ectropin?

A

excessive watery eye. falling away of lower lid from eye or globe. not good blinking. orbicularis occuli effected. senile ectropion is secondary loss of tone and fat deep around globe due to age..

45
Q

what is entropion?

A

A turning in of the eyelid.
Cicatrical entropion with resulting trichiasis (contact bw eyelid and corneal surface).
Characteristic with trachoma (Chlamydia infection) and ocular pemphigoid .
causes cornea to become opaque.

46
Q

explain exophthalmus

A

found in thyroid disease. Retraction of the upper eyelids causes a widening of the palpebral fissure
Thyroid eye disease: Exophthalmometry measurements are remarkably similar to normal patients
Vertical fissure measurements are better.
Measurements ranging from 12 to 21 mm are obtained in normal subjects with a mean of 16 mm, while those with thyroid eye disease yield values ranging from 12 to 24 mm with a mean of 18 mm. Measurements of greater than 19 mm however, were found in only about 5% of normals, while 32% of those with thyroid eye disease fell above this level.
The principal component in the apparent exophthalmos of thyroid eye disease is the degree of lid retraction. Thus measurement of the vertical palpebral fissure width may be a more important measure than exophthalmometry.

47
Q

what is collier’s sign?

A

retraction of upper eye lid. Type of Thyrotoxicosis. when one eye is more open or projected than the other expect thyroid disease.

48
Q

what is von grafe’s sign?

A

delay of movement of the upper lids when shifting gaze up and down; causing a staring expression. A lid lag.
Type of Thyrotoxicosis.

ocular physiology (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions