Adenexa and Anatomy of Eyelid Flashcards
What muscles move the eyebrows?
Frontalis, corrugator, procerus, orbicularis
What effect does frontalis have on the eyebrow?
Elevation (as in surprise)
What effect does corrugator have on the eyebrow?
Pulls medial sides of eyebrows together (as in concentration)
What effect does procerus have on the eyebrow?
Pulls medial eyebrow down and medially (as in agression)
What effect does orbicularis have on the eyebrow?
Lowers eyebrow
The palpebral sulci divide each eyelid into what two portions?
Orbital portion (from sulcus to brow or cheek); tarsal portion (from sulcus to lid margin)
What is the plica semiluminaris, and what is its function?
A fold of conjunctiva at the medial canthus that allows for lateral globe movement without stretching the conjunctiva. It also forms the floor of the lacrimal lake.
Define caruncle
A mass of modified skin at the medial canthus; it forms the medial wall of the lacrimal lake.
Name the muscles of the eyelid
Orbicularis oculi, superior palpebral levator, superior tarsal muscle (of Muller), inferior tarsal muscle (of Muller)
What is the action of the orbital portion of the orbicularis oculi?
A sphincter-type contraction (runs from medial palpebral ligament to medial palpebral ligament)
Into what two muscles is the palpebral portion of the orbicularis oculi divided?
Horner’s muscle (around lacrimal canalliculi for tear drainage); Riolan’s muscle (along lid margin to adhere lid to globe)
What is the origin of the superior palpebral levator?
Lesser wing of sphenoid
What is the insertion of the superior palpebral levator?
Tarsal plate and dermis of eyelid
What is the aponeurosis?
A fan-shaped tendon of insertion of the superior palpebral levator
Name the two portions of the aponeurosis.
Medial horn and lateral horn (the lateral horn divides the lacrimal gland into an orbital portion and a palpebral portion)
