Eyelids And Lacrimal Flashcards
Eyelids function
Palpebral
-protection (lashes =xdust)
-closure-control light
-distribute TF (blinking)
Superior palpebral sulcus
Top lid of eyelid
Covers 1/6cornea
Larger than inferior
Lower in SE Asians, so affects CL
Palpebral fissure?
Limits of eyelids (VPA and horizontal)
Droopy lids =ptosis= small palp fissure
Describe canthi
2-medial(nasal) and lateral
Medial in contact with eye
Lateral is operated from eye by tear lake
Caruncle and plica semilunaris
No function
Caruncle has seb glands and hairs
Ploca is highly vasc fold of conjunctiva
Eyelid margin
2mm x 30mm
2 parts:medial lacrimal (glands)
lateral ciliary(lashes/cilia)
Cilia in 2or 3 rows
Upper lid has more and longer cilia
(100 to 150) vs (50 to 75)
‘Grey’ line divides anterior (cilia) and posterior (glands)
Stages of eyelash growth
Anagen (30 to 45 days)
Catagen ( 2 to 3 weeks)
Telogen( 3 to 4 months) - shed
Anagen
What is a stye and why it forms?
External hordeolum
Inflammation in meibo gland
2 glands in cil zone?
Glands of Zeis -Seb glands/oil secretion to lubricate lid margin and prevent tear evapo
Attached to hair follicle
Glands of Moll -sweat glands/clear secretion
On the side of hair follicle
Layers of internal eyelid from outermost to innermost?
Skin
Subcutaneous tissue
Striated msc
Sub-muscular connective tissue
Fibrous tissue
Non striated msc
Conjunctiva
External skin
Thinnest - ease of blink
Lid laxity increase with age - dermatochalasis
No fat so easily distended
Which striated msc is used in closing the eyelid? How many parts?
Orbicularis ocular
3 parts: palpebral (Pre tarsal and pre septal )
Orbital
Lacrimal
Orb. Oculi ?
Medial and lateral palp ligament
Function: forced closure of lids(orbital)
Gentle closing of lids(palpebral)
Pumping mechanism(lacimal)
Innervation: temporal and zygomatic branch Cr. N VII (Facial)
Other muscles with Orb. Oculi?
Riolans msc-maintains psn of lid margin to globe
Horners msc- surrounds lacrimal for tear drainage
