Lecture 11 Ocular adenexa and lacrimal apparatus 1

describe the anatomy of the eyebrows

thick skin covered by short, prominent hairs extending across the superior orbital margin

nerve supply of eyebrows

CN VII

muscles of the eyebrows

frontalis, corrugator supercilli, procerus, orbicularis oculi, depressor supercilli

function of the frontalis muscle in eyebrows

raise the eyebrow (surprise or attention)

which eyebrow muscle is responsible for raising the eyebrow (surprise or attention)

frontalis

function of the corrugator supercilli muscle in eyebrows

move eyebrow medially (trouble or concentration)

which eyebrow muscle is responsible for moving eyebrow medially (trouble or concentration)

corrugator supercilli

function of the procerus muscle in eyebrows

pulls the medial side of eyebrow medially (menance or aggression)

which eyebrow muscle is responsible for pulling the medial side of eyebrow medially (menance or aggression)

procerus

protective functions of eyebrows

To protect eyeball against injury from superior side.

To protect eye from bright sunlight.

Abundant sensory innervation of supercilia helps in sensing tactile stimulation and reacts accordingly.

what structure has this function: To protect eyeball against injury from superior side.

eyebrows

what structure has this function: To protect eye from bright sunlight.

eyebrows

function of abundant sensory innervation of supercilia

helps in sensing tactile stimulation and reacts accordingly.

function of eyelid

operates opening and closing the eye

what is the palpebral fissure of the eyelid

Exposed zone between the upper and lower eyelids

which eyelid is more mobile

upper eyelid

which eyelid is less mobile

lower eyelid

which muscle is responsible for opening of eyelid

Levator palpabrae superioris (LPS)

which nerve innervates the levator palpabrae superioris (LPS)

CN III

which muscle is responsible for closing of eyelid

Orbicularis oculi

which nerve innervates the orbicularis oculi

CN VII

Levator palpabrae superioris (LPS) is responsible for what action

opening of eyelid

orbicularis oculi is responsible for what action

closing of eyelid

vascular supply of upper eyelid

internal carotid artery

pathway of vascular supply for the upper eyelid

internal carotid artery —> ophthalmic artery —> superior marginal arcade

the internal carotid artery supplies what structure in our eye

upper eyelid

vascular supply of inferior eyelid

the external carotid artery

pathway of vascular supply for the inferior eyelid

external carotid artery —> facial artery —> angular artery —> the inferior marginal artery

the external carotid artery supplies what structure in our eye

inferior eyelid

venous drainage pathway of eyelid

angular vein —> common facial vein —> internal jugular vein

branches of angular vein

medial palpebral vein —> superficial temporal vein —> lateral palpebral vein —> inferior palpebral vein

The majority of the upper eyelid and the outer half of the lower eyelid drain into where

pre-auricular lymph nodes

what parts of the eye drain into the pre-auricular lymph nodes

majority of the upper eyelid and the outer half of the lower eyelid

A small part of the middle of the upper eyelid and the inner half of the lower eyelid drains into where

submandibular lymph nodes

what parts of the eye drain into the submandibular lymph nodes

A small part of the middle of the upper eyelid and the inner half of the lower eyelid

size of eyelid margin

2mm broad

eyelid margin divided into what parts

the medial, lacrimal portion and lateral, ciliary portion

eyelid margin divided into two parts by what

punctum

describe the medial, lacrimal portion of the eyelid

rounded and devoid of lashes or glands

which portion of the eyelid is rounded and has devoid of lashes or glands

medial, lacrimal portion

describe the lateral, ciliary portion of the eyelid

a rounded anterior border, a sharp posterior border and an inter-marginal strip

which portion of the eyelid has a rounded anterior border, a sharp posterior border and an inter-marginal strip

lateral, ciliary portion

lifespan of eyelashes

100-150 days

term for extra layer of eyelashes

distichiasis

term for eyelashes that curve inward

trichiasis

term for inward-turned eyelid

entropion

term for outward-turned eyelid

ectropion

term for inflammation of the oil glands

blepharitis

term for excessive lash growth

trichomegaly

palpebral fissure size horizontally, in regular adult

25-30 mm

palpebral fissure size vertically, in regular adult

10-12 mm

main structures of eyelid

skin, striated muscles, fibrous layer, smooth muscle, conjunctiva

name the important striated muscles of eyelid

orbicularis oculi, levator palpabrae suerioris (LPS)

what kind of muscles are these structure: orbicularis oculi and levator palpabrae suerioris (LPS)

striated muscles

two parts of the fibrous layer of eyelid

orbital septum and tarsal plate (palpebral fascia)

orbital septum and tarsal plate are part of what layer in the eyelid

fibrous layer

function of fibrous layer of eyelid

forms the dense skeletal framework and structural support of the lids

if we open our eye, what happens to the orbicularis oculi and canaliculi

orbicularis oculi relaxed —> open canaliculi —> lacrimal sac retracts (negative pressure)

orbicularis oculi relaxed —> open canaliculi —> lacrimal sac retracts (negative pressure): OPEN OR CLOSE EYES

open eyes

if we close our eye, what happens to the orbicularis oculi and canaliculi

orbicularis oculi contracts —> close orbicularis oculi —> lacrimal gland expands

orbicularis oculi contracts —> close orbicularis oculi —> lacrimal gland expands: OPEN OR CLOSE EYES

close eyes

the two plates of tarsal plate are composed of what tissue

dense connective tissue

function of the tarsal plate in eyelid

give shape and firmness to eyelids

function of Meibomian glands embedded in tarsal plate of eyelid

The Meibomian Glands lying in parallel rows, which produce oils for the tear film

what is the septum orbital (palpebral fascia) in the eyelid

A thin membrane of connective tissue perforated by nerves, vessels and LPS muscle, which enter the lids from the orbit

what structure is this describing: A thin membrane of connective tissue perforated by nerves, vessels and LPS muscle, which enter the lids from the orbit

septum orbitale

what kind of muscle is the Tarsal/Muller muscle

smooth muscle

what muscle is the Muller muscle consisted of

palpebral muscle of muller

where does the palpebral muscle of muller lie in our Muller muscle

deep to the septum orbitale in both the lids

where does the Muller muscle arise from in the upper eyelid

from the fibres of LPS muscle

where does the Muller muscle arise from in the lower eyelid

from prolongation of the inferior rectus muscle

where is Muller muscle inserted in the tarsal plate

on the

peripheral margins of the tarsal plate

what nerve supplies the Muller muscle

sympathetic fibres of when CN III

where can we find Meibomian gland

in stroma of tarsal plate arranged vertically

which eyelid contains more Meibomian gland

upper eyelid

what does each Meibomian gland consist of

central duct that runs vertically through the length of the tarsal plate and acini that are arranged on two sides of the duct

what is the opening of the duct at lid margin in the Meibomian gland

secretory duct

the acini and central duct surface of the Meibomian gland is lined with what cells

epithelial cells

what are Glands of Zeis and Moll

specialized exocrine glands located along the margin of the eyelid near the base of the eyelashes

what kind of gland is Glands of Zeis

Modified sebaceous (oil-producing) glands (same as meibomian gland)

where can we find Glands of Zeis

Attaches directly into the follicles of eyelashes - on roots of eyelash

function of Glands of Zeis

Its secretion prevents eyelashes from being dry and brittle

which gland is responsible for preventing eyelashes from being dry and brittle

Glands of Zeis

function of Glands of Moll

produce watery or serous secretions that add antimicrobial agents to the tear film to help fight bacteria

which gland is responsible for producing watery or serous secretions that add antimicrobial agents to the tear film to help fight bacteria

Glands of Moll

where kind of glands is Glands of Moll

Modified apocrine sweat glands (aka ciliary glands)

where can we find Glands of Moll

on the margin of the eyelid (more in lower than upper) - between eyelashes

main functions of eyelid

• Reconstitution of the tear film.

• Maintain the integrity of the corneal surface.

• Maintain the proper position of the globe within the orbital contents.

• Regulate the amount of light allowed to enter the eye.

• Protect from airborne particles.

• Coverage of the eye during sleep

what structure is responsible for this function: Reconstitution of the tear film.

eyelid

what structure is responsible for this function: Maintain the proper position of the globe within the orbital contents.

eyelid

what structure is responsible for this function: Maintain the integrity of the corneal surface.

eyelid

what structure is responsible for this function: Regulate the amount of light allowed to enter the eye.

eyelid

what structure is responsible for this function: Protect from airborne particles.

eyelid

what structure is responsible for this function: Coverage of eye during sleep

eyelid

name the eyelid movements

lid opening, lid closing, blinking, voluntary blinking and winking, Bell’s phenomenon

which structure controls the vertical position and opening of the eyelids

upper lid elevators and lower lid retractors

main function of the upper lid elevators and lower lid retractors

control the vertical position and opening of the eyelids

important muscles of the upper lid elevators

levator palpebrae superioris, superior palpebral muscle of Muller’s, and frontalis

what is the primary elevator of the upper eyelid

Levator palpebrae superioris

which muscle act as the accessory elevator in the upper lid elevators

frontalis