week 7 Flashcards
which part of the eyelid is the most moveable
upper eyelid
what are the sections of the upper eyelid
Orbital region – extends over the orbit
Tarsal region
Between = orbitaopalpebral sulci
Preseptal part
Pretarsal part
what is the gap between the eyelid
palpable aperture
what does the punctum do
where tears drain away
what is the lachrymal region
towards the back and sandwhiches the tears
Eyelid layers
how many layers in epidermis layer
6/7 layers of epithelial skin cells
what glands are in the skin layer
glands of zeis + moll - oily secretion to keep skin soft and hairs soft to keep moisturised
sweat glands to keep the skin cool
name of eyelashes
cilium
10 weeks to grow back
dont stand up when its cold
what muscles close the eye
orbicularis oculi muscle
what does the frontalis muscle do
Controls the upper part the eyelid if the levator doesn’t work
what does the orbital part of the eye do
responsible for forcing the eye shut
what does the Levator palpebrae superioris muscle do
lifts the eyelid up
what does the muscle of riolan do
Provides muscle power or tension to the ends of the eye so they don’t flap around
what is tarsal muscle
smooth muscle
controlled by TNS
what are the tarsal plate seperated into
superior
inferior
what is the tarsal plate made up of
dense connective tissue to provide shape to the eyelid
what do the tarsal glands do
produce oily substance for tear film to prevent tears from evaporating
if blocked up it can produce Meibomian gland dysfunction
what does the orbital septum do
connected to tarsal plate/connected to periorbita
keeps orbital contents in the orbit
sections of the conjunctiva
draw it
marginal
tarsal
palpebral
upper fornix
bulbar
limbal
what is the marginal conjunctiva
where skin meets the conjunctiva
what does the tarsal conjunctiva do
where nutrients form in front of cornea
what does the palebral conjunctiva do
glands near the fornix contain mucus producing globlet cells to help tear film stick to microvilli
what do lacrimal glands produce
watery part of the tear film
what glands produce also produce the watery part of the tear film
glands of krause and glands of wolfing
what is the structure of the upper fornix
bends back on itself
where does the bulbar conjunctiva sit
sits on the roundest part of the eye
what is the limbal conjunctiva
last section
what are the 3 phases of tear film
oily phase
watery phase
mucus phase
how do tears drain
tears pass across the cornea in the lacrimal rivers
what structures are invoved in tear drainage
punctum
ampulla
caliculu
sinus of Maier
lacrimal sac
into the naso-lacrimal duct which drains through the valve of hesner into the nasal meatus
stage 1 of the lacrimal pump
eye open
orbicularis oculi muscle relaxed
tears drawn to punctum by capillary action
expansion of the canaliculi
stage 2 of the lacrimal pump
eye closed
contraction of
orbicularis muscle
horners muscle
preseptal part of orbicularis causing expansion of lacrimal sac drawing tears from canaliculi
valve of hasner closes preventing backflow
stage 3 of lacrimal pump
eye opens
contraction of lacrimal sac
tears to neolacrimal duct then nasal meatus
tubuloracemose structure
consists of small sacs lined with secreting cells
small tubes link acini to form lobules
