Lids

Question 1

function of levator

Answer 1

raises upper eyelid and works with orbicular in both involuntary blinking and forced lid closure

Question 2

levator innervated by:

Answer 2

CN III

Question 3

3 causes why levator causes ptosis

Answer 3

1. mechanical ptosis (hordeolum, chalazion, zit)
2. myogenic “ptosis”
3. neurogenic “ptosis” (innervation, CNIII)

Question 4

function of Mueller’s muscle:

Answer 4

• maintains tons of elevated upper lid

- maintains tons of opened lower lid

Question 5

Mueller’s muscle innervated by:

Answer 5

sympathetic NS

Question 6

dysfunction of Mueller’s muscle causes:

Answer 6

slight ptosis, inverse ptosis (1-3mm)

Question 7

function of orbicularis muscle

Answer 7

• closes lids (involuntary regular blinking, forced voluntary blinking)
• maintains apposition of lacrimal drainage apparatus against globe

Question 8

orbicularis muscle innervated by

Answer 8

CN VII (7)

Question 9

shape and attachment of orbicularis muscle

Answer 9

elliptically shaped, attached nasal and temporal edges of orbit by medical an lateral palpebral ligaments

Question 10

“palpebral” part of orbicularis is responsible for

Answer 10

involuntary blinking

Question 11

“orbital” portion in forehead, temples, and cheeks is responsible for

Answer 11

forced lid closure

Question 12

lesion of CN VII causes:

Answer 12

paresis or paralysis of orbicularis and also some facial muscles

• Bell’s palsy
• Lagophthalmos

Question 13

loss of tons of orbicularis and its ligaments causes

Answer 13

puncta to fall away resulting in epiphora

Question 14

what is entropion resulting from?

Answer 14

due to reduced tons of lower orbicularis with inability to return lower lid margin to its normal position

Question 15

what 2 glands are located near the lash follicle?

Answer 15

• glands of Moll (sweat)

- glands of Zeis (sebaceous)

Question 16

where are Meibomian glands located?

Answer 16

deep in the tarsal plate

Question 17

what is the purpose of the tarsal plate?

Answer 17

fibrous “skeleton” of lids, gives shape and firmness to eyelids

Question 18

lateral half of eyelids lymphatics drain into the:

Answer 18

preauricular lymph node

Question 19

medial half of eyelids lymphatics drain into the:

Answer 19

submandibular lymph node

Question 20

the nerves motor supply is by the:

Answer 20

• orbicularis supplied by CN VII

- levator supplied by CN III

Question 21

the nerves sensory supply is by the:

Answer 21

CN V trigeminal

-first 2 divisions (V1 ophthalmic and V2 maxillary)

Question 22

most common 2 bacteria cultured from normal eyes are

Answer 22

S. epidermis and S. aureus