Eyelids Flashcards
Folds of skin and tissue that, when closed, cover the globe
Eyelids
When the eyelids are closed gently, the eyelids should
Cover the entire globe
Which eyelid is larger and more mobile?
Upper
Whihc eyelid is more variable?
Lower lid
Where do the eyelids meet?
Lateral canthus and medial canthus
Lateral angle (lateral canthus)
Directly in contact with the eyeball
The medial angle (canthus)
Lose about 6mm medially from the eyeball
What are the two eyelids separated by in the medial canthus
Locus lacrimalis
What is in the middle of the locus lacrimalis?
Caruncula lacrimalis
Plica semilunaris
Exposed zone between the upper and lower eyelids
Palpebral fissure
Eyelid functions
- Cover the globe for protection
- Move the tears toward drainage at the medial canthus on closure
- Spread the tear film over the anterior surface of the eye on opening
- Contain structures that produce the tear film
Layers of the eyelid
- Skin layer
- Subcutaneous areolar layer
- Orbicularis layer
- Submuscular areolar layer
- Orbital septum
- Posterior muscular system
- Tarsal plate
- Palpebral conjunctiva
Thin layer of skin that contains fine hairs, sweat, and sebaceous glands
Skin layer of the eyelid
Thinnest skin on the body and contains no fat
Skin layer of the eyelid
Thin layer of loose connective tissue that lies between the outer skin and underlying orbicularis
Subcutaneous areolar layer of the eyelids
The upper lid subcutaneous areolar layer contains what as it travels to its insertion within the skin and upper tarsal plate
The levator aponeurosis
Contains palpebral portion of the orbicularis oculi
Orbicularis layer
What is the orbicularis muscle innervated by?
Facial
Attaches to orbital margins, extends outward
Orbital portion of eyelid
Used for forced closure of the eyelids
Orbital potion of orbicularis layer of the eyelid
Used for spontaneous and relfex blinking
Palpebral portion of the orbicularis layer of the eyelids
What are the two specialized areas of the palpebral potion of the orbicularis layer of the eyelid
- muscle of riolan (pars ciliaris)
- muscle of Horner
Functional labeling of the orbicularis oculi
Orbital and palpebral
Anatomical labeling of the orbicularis oculi
- pretarsal
- preseptal
- orbital
The superficial portion of the orbicularis oculi that keeps the lid margin tightly applied to the globe during eye movements
Muscle of riolan
The most anterior portion of the gray line
Muscle of riolan
A groove located between the eyelash insertions and the meibomian glands
Gray line
Divides the lid into anterior and posterior portions and serves as a surgical landmark during lid repair
Gray line
Consists of fibers from the orbicularis that encircle the canaliculi and help drain tears into the lacrimal sac
Muscle of Horner (pars lacrimalis)
Thin layer of loose connective tissue that lies between the orbicularis and the orbital septum
Submuscular areolar layer of the eyelids
The upper lid submuscular layer contains what
Levator aponeurosis and the palpebral portion of the main lacrimal gland
Dense irregular layer of loose connective tissue that serves as a barrier to the orbit in the upper and lower eyelids
Orbital septum
Keeps infections localized to the anterior portion of the eyelid, away from the orbit
Orbital septum
Does not protect the lacrimal sac from infections
Orbital septum
Serves as the insertion site for the levator aponeurosis
Superior orbital septum