Anatomy Of The Eyelids Flashcards
What are the functions of the eyebrows?
Emotion (facial expression)
Protection
What are the muscles of facial expression?
Frontalis elevates eyebrow
Orbital portion of the orbicularis oculi lowers eyebrow and closes the lid
Innervated by 7 (facial nerve)
Procerus depresses medial eyebrow
Corrugator supercilii pulls eyebrow medially
(Fast puppies obtain chocolate)
What is facial nerve palsy?
Problem with 7th cranial nerve
Eyes cannot close and dry out
What are the functions of the eyelids (palpebrae)?
Protect eye from injury
Protect eye from excessive light
Spread tears
Locate the anatomy of the eyelid.
Orbital portion
Tarsal portion
Superior palpebral sulcus
Inferior palpebral sulcus
Palpebral fissure (9-10mm)
Lateral canthus
Medial canthus
What is the anatomy of the medial canthus?
Caruncle
Pelican semilunaris
Papilla
Lacrimal punctum
Pores of meibomian gland
Cilia
What are the dimensions of the lid margin?
30mm in length
2mm in width
Describe the cilia on the lid margin.
In anterior lamella
2 rows superior
1 row interior
Describe the puncta on the lid margin.
Superior and inferior in canthal region
Opening within lacrimal papilla
Describe the mucocutaneous junction of the lid margin.
Junction between skin an palpebral conjunctiva
Gray line
Surgical landmark separating anterior and posterior lamella
Clinical correlates of lid margin?
Trichiasis
Epicanthic folds
What is the anatomy of the anterior lamella (lid anatomy)?
Eyelid skin
Orbicularis muscle
Lashes
Glands
Levator aponeurosis
“Even old Larry got lit”
What is the anatomy of the posterior lamella (lid anatomy)?
Tarsal (meibomian glands)
Palpebral conjunctiva
Accessory lacrimal glans
Muller muscle
“The pig ate mud”
What are the muscles of the eyelid and their functions?
Orbicularis oculi (lid closure, tear maintenance)
Levator (raises lid)
Muller’s muscle (superior tarsal muscle) assists levator
Inferior tarsal muscle (depresses the inferior lid)
What are the parts of the orbicularis oculi? What nerve innervates it?
Orbital – voluntary: closes the lids and lowers the brow
Palpebral – involuntary: blink
Lacrimal (Horner’s muscle) – moves tears
Ciliary (muscle of Riolan) – maintains lid apposition (next to eye)
7th (facial) nerve
What are the glands of the anterior lamella?
Glands of Zeiss- sebaceous
Glands of Moll- Sweat
What are the glands of the posterior lamella?
Meibomian glands- sebaceous
Accessory lacrimal glands- aqueous portion of tears
Describe sensory innervate on to eyebrow and eyelids.
Through CN5
V1 innervates upper eyelids, nose, medial forehead
V2 innervates lateral eyelid, cheek, upper lip
V3 innervates lateral forehead, part of ear, lower cheek, lower lip
Arterial lid vasculature
Peripheral arcade- ICA
Marginal arcade- ECA
Highly vascularized supplies by internal and external
Venous lid vasculature
Outer- jugular
Inner- ophthalmic, cavernous sinus
Superfical lid lymphatics
Drain skin and orbicularis
Deep lid lymphatics
Drain tarsal plate and conjunctiva
Eventually drains into superfical parotid nodes and submandibular nodes
Motor lid innervation
Open lid – III to levator
Close lid – VII to orbicularis
Sensory lid innervation
V1 to upper lid (lacrimal, supra-orbital, supratrochlear)
V1 (lacrimal) and V2 (infraorbital) to lower lid
V1 (infratrochlear) to medial commissure
Autonomic lid innervation
Open lid – sympathetic to Muller muscle
What is the purpose of the structure surrounding the eyeball?
Maintains eye position keeping it controlled as you look around.
Describe tenon’s capsule (fascia bulbi).
Envelope of connective tissue
Protection
Attachment of EOM’s
Fuses with optic nerve sheath posteriorly
Intermuscular septum anteriorly
Describe what surrounds the eyeball from the outside in.
Outer
Bulbar conjunctiva
Tenon’s capsule (from optic nerve to limbus)
Episclera
Sclera
Inner
What are the purposes of check ligaments and the suspensory ligaments?
Check ligaments prevent eyeball from overshooting
Suspensory ligaments expends from lateral to medial check ligaments, prevent the eyeball from uncontrollable movement.
Describe the orbital septum.
Supports the lid
Membranous fibrous sheet
Separates the lid and the fat that fills the orbit
Describe the tarsal plates.
Maintains firmness and shape of lid
Dense fibrous connective tissue
Superiorly 10-11mm; inferiorly 5mm
