Palpebrae Flashcards
Palpebrae function
Protects eye Senses via lashes Maintains eye position Drains / distributes tears Produces tears Blinks for tear renewal
Palpebral fissure structure
Upper lid, nasal/temporal canthus, lower lid
Caruncle (fleshy protrusion on nasal side)
Plica semilunaris (binds caruncle to sclera)
Facial folds of palpebrae
Superior palpebral sulcus (upper lid fold)
Inferior palpebral sulcus (lower lid fold)
Palpebrae layers from outside to inside
Skin Subcutaneous areolar (loose connective tissue) layer (connective tissue with LPS tendons) Striated muscle Submuscluar areolar layer Orbital septum and tarsal plate Smooth muscle Conjunctiva
Palpebrae skin layer
Has glands of zeis (sebaceous), glands of Moll (sweat), meibomian glands (oil into tear film, whit spots)
Subcutaneous areolar layer
Loose connective tissue, pierced by levator palpebral superiors tendon
Glands of the palpebrae
Glands of zeis(subaceous), open into lash follicles
Glands of Moll(sweat) open onto lid surface
Meibomian glad, opens where skin meets conjunctiva
Lacrimal gland assistors (krause / wolfring) in conjunctiva
Meibomian glands
Sebaceous (oil), in tarsal plate, assists tear film stability (less evaporation), rich innervation.
Small lumps below lash or large in outer lid indicate disorder.
Glands of moll
Ciliary glands, sweat behind lash
Glands of zeis
Sebaceous, discharge into lash for lash protection.
Striated muscle of palpebrae
Orbicularis oculi: outer rings of muscle
Muscle of riolan: ciliary portion (around fissure)
Lateral palpebral raphe: upper eyelid
Sub muscular areolar layer of palpebrae
Visible grey section of palpebrae. Oedema on inflammation
Muscles in blinking.
Orbicularis oculi muscles with CN VII innervation:
Palpebral - gentle closure
Orbital - forceful closure
Muscle of Riolan - lid margin and globe positioning
Muscles in opening and closing eye
Levator palpebrae superioris(LPS) - elevates upper lid via striated muscle with CNIII (oculomotor) innervation.
Muscle of muller - assist lid position / upper lid elevation via smooth muscle, active in flight/fight via sympathetic NS
Eyelid malposition’s
Entropion - inward turning of lid Ectropion - outward turning of lid Blepharospasm - involuntary contraction Lid retraction - thyroid eye disease Jaw winking syndrome - abnormal sunkinesis CN3/5
Orbital septum and tarsal plate
Tarsal plate: Central plate in lids with Meibomian glands, anchors palpebral ligaments and LPS.
Orbital septum: Thin peripheral outer layer from tarsal plate, enters orbit, attaching to orbit bones.
Palpebral vasculature
Lateral palpebral arteries (branch of lacrimal artery)
Medial palpebral arteries (sup./inf.) branch from ophthalmic artery.
Drained into ophthalmic and angular veins (medial part), and superficial temporal vein (temporal part)
Lymphatic drainage of palpebrae
Medial part by submandibular nodes
Lateral part by superficial parotid nodes
Smooth muscular layer of palpebrae
Muscle of muller. Forms upper (LPS lid elevation assistance) / lower (lowers lid assisting inferior rectus). These are superior and inferior tarsal muscles, attached to tarsal plate with sympathetic innervation.
Conjunctiva
Mucous membrane, with goblet cells / crypts of henle / glands of maz.
Continuous with sub muscular areolar, joins cornea near limbus.
Bulbar covers eye, Forniz connects lit to eye, palpebral is on lid.
Goblet cells of palpebrae
Secret mucin. Present in crypts of Henle (palpebral conj.) and glands of Manz (limbus)
Palpebral vasculature
Lateral palpebral arteries. Drains into ophthalmic vein, to submandibular lymph nodes
Medial palpebral arteries (superior and inferior), run along top and bot lids from ophthalmic artery. Drains into superficial temporal vein into superficial parotid nodes
Palpebral innervation
Sensory: 5 branches from CN 5 (trigeminal).
Muscle:
Orbicularis oculi, temporal / zygomatic branches of CN VII (facial)
Muscle of muller, sympathetic NS by superior cervial sympathetic ganglion
Levator palpebrae superioris (LPS), superior division of CN III (oculomotor)
Eyebrow muscles
Innervated by CN 7 Frontalis - elevates brow Orbicularis oculi (orbital part)- lowers brow Corrugator - contracts down and medially Procerus - nose wrinkling