1.07 Eyelids and lacrimal system Flashcards
layers of the eyelids
- external skin
- subcutaneous tissue
- orbicularis muscle
- Aponeurosis and levator muscle
- palpebral conjunctiva
what are tarsal plates good for
- Give eyelids its shape
- Have some structural rigidity
- The muscles that control the eyelids are attached to the tarsal plate
- tarsal plate is found both in upper and lower lid
what is another name for tarsal plates
meibomian glands
What are the two muscles involved in widening the palpebral aperture (elevating upper eyelid)
The levator palpebrae superioris (levator) and the superior tarsal muscle (muellers muscle)
what are the muscles involved in allowing the bottom eyelid to stay open
inferior tarsal plate
which muscle narrows the palpebral aperture?
orbicularis oculi
what are the different types of blinks
Reflex blink - to stop things getting into eye
spontaneous blinking - the blinking you do not think about, you just do it to refresh the tear film
voluntary blinking - blinks that you think more about e.g. closing eyes to sleep
glands of Zeis
produce an oily substance which lubricates the eyelash and helps with capturing dust
Glands of moll
is not a part of the eyelash follicle system, these are modified sweat glands, they have rings of secretary cells around a large lumen.
what is the proper terms for eyelids turning out or inwards
what about eyelashes turning in
ectropion or entropion
trichiasis
which structure keeps the orbital fat in its place
orbital septum (barrier)
which glands secrete the lipid portion of the tear film
meibomian glands
what is the structure of the tear film
lipid layer - meibomian glands, zeis and moll
aqueous layer - main lacrimal gland and accessory lacrimal glands
mucus layer - goblet cells in conjunctiva
