Eye & Eyelid Flashcards
Choose 1:
Eyelashes are located anterior/posterior to pores of meibomian glands.
anterior
Define gray line:
Groove that runs between eyelashes and pores of meibomian glands
The most anterior part of muscle of riolan is:
gray line
Functions of the eyelids:
- Cover globe for protection
- Move tears towards drainage at medial canthus upon closure
- Spread tear film over anterior surface of eye upon opening
- Contain structures that produce the tear film
Name all the glands of the eyelid:
- Meibomian glands
- Glands of Wolfrig
- Glands of Krause
- Glands of Zeis
- Glands of Moll
These glads are located in tarsal plates:
Meibomian glands
Choose one:
Meibomian glands make up a(n) watery/oily layer.
Oily
Glands of wolfrig make up an ______ layer and are located near ______.
Aqueous; tarsal plates
This gland is an aqueous layer and located in fornix:
Gland of Krause
Glands of Zeis secretion is _____ and are located _________.
Sebaceous; at the base of hair follicle
Eyelash lubrication is done by this gland:
Gland of Zeis
Sudiferous secretions are from ___________, which are located ________________.
Glands of Moll; adjacent to hair follicle base
Lacrimal gland is located:
within lacrimal fossa of the frontal bone
Palpebral and orbital portions of the lacrimal gland are divided by ____________.
Tendon of levator palpebrae superioris
_____________ connect lacrimal puncta to lacrimal sac
Canaliculi
What makes the superior palpebral sulcus?
LPS inserts into eyelid skin to produce superior eyelid crease
How is inferior palpebral sulcus produced?
Eyelid skin is tethered to underlying periosteum
The gray line in the most anterior part of ____________ and is in the _________ part of orbicularis oculi muscle.
Anterior; Palpebral
What structure has this function:
Keeps lid margins apposed to globe
Gray line
Mucocutaneous junction is in the ____________ edge of the eyelid.
Posterior
What are the structures of the eyelid margin?
- Meibomian Orifices
- Gray line (muscle of Riolan)
- Lash line and eyelashes
Identify the structure:
It is the surgical division between anterior and posterior parts of the eyelid.
Gray line
What are the layers of the eyelid?
- Skin
- Subcutaneous areolar layer
- Orbicularis layer
- Sub-muscular areolar tissue
- Orbital septum
- Posterior muscular system (LPS + Muller’s)
- Tarsal plate
- Palpebral conjunctiva
Thinnest skin of the body is located:
on the eyelids
Skin of the eyelids do not contain any ____.
Fat
Skin of the eyelid contains:
- Fine hair
- Sweat glands
- Sebaceous glands
This layer of the eyelid contains no fat and blood and edema can easily pool in it.
Subcutaneous areolar layer
Subcutaneous areolar layer is a loose CT between __________ and ___________.
Skin; orbicularis layer
What is contained in the orbicularis layer of the eyelid?
- Orbital portion
2. Palpebral portion
What is contained in the palpebral orbicularis layer?
- Muscle of Riolan
- Muscle of Horner
Orbital orbicularis layer function:
Forced closure of eyelids
This layer of the eyelid is used for spontaneous and reflex blinking
Palpebral orbicularis layer
Sub-muscular areolar tissue is what type of CT and is between which layers of the eyelid?
Loose; orbicularis oculi and orbital septum
This layer communicates with subaponeurotic layer of the scalp:
Sub-muscular areolar tissue
Raccoon eyes are associated with which layer of the eyelid?
Sub-muscular areolar tissue
Orbital septum is a _____ CT.
Dense
Functions of the orbital septum:
- Restricts fat from falling onto lid margins
- Prevents superficial infections from spreading into the orbit
Identify the structure:
Runs from entire orbital rim to tarsal plates of eyelids and is extension of periorbita:
Orbital septum
Identify the structure:
Dense irregular connective tissue that is made up of collagen fibrils that surround the meibomian glands.
Tarsal plate
Tarsal plate function:
To provide rigidity to the eyelids
What is the function of LPS?
It retracts the upper eyelid
LPS is innervated by:
CN III
LPS origin and insertion:
Origin: Sphenoid bone
Insertion: Tarsal plates and the skin of the eyelid as levator aponeurosis
Identify the structure:
fan-shaped tendinous expansion posterior to the orbital section.
LPS
Fibers of LPS penetrate ______ and attach to ______ and eyelid.
septum; tarsal plates and eyelid
LPS divides ________ into orbital and palpebral lobes.
Lacrimal gland
Muller’s muscle is aka:
Superior tarsal muscle
This muscle is innervated by the sympathetic nervous system.
Muller’s muscle (superior tarsal muscle)
Function of Muller’s muscle:
Widens the palpebral fissure by 2-3 mm
Identify the structure:
It is the minor retractor of the upper eyelid.
Muller’s muscle
Muller’s muscle origin:
LPS
Muller’s muscle insertion:
Tarsal plate
What is the palpebral conjunctiva?
It is a mucous membrane made up of non-keratinized squamous epithelium and goblet cells.
Function of the goblet cells:
Produce mucin layer of the tear film
True/false:
Epithelial later of palpebral conjunctiva has a stratified protective layer.
True
Stroma of palpebral conjunctiva is what type of tissue?
Loose vascularized CT
___________ of palpebral conjunctiva contains accessory lacrimal glands, nerves, and blood vessels.
Stroma
Identify the ligament:
Forms hammock below the eyeball to provide support.
Suspensory ligament of Lockwood
Suspensory ligament of Lockwood encloses these muscles:
- IR
- IO
Which ligament provides suspensory support for upper eyelid?
Whitnall ligament
Whitnall ligament function:
Surrounds LPS and causes it to have superior vector pull
These ligaments attack to superior and inferior tarsal plates:
Medial and lateral canthal ligaments
What are the components of the lacrimal aparatus?
Lacrimal gland and accessory lacrimal glands
What are the constituents of the nasolacrimal drainage system?
-Lacrimal puncta
-Canaliculi
-Lacrimal sac
Nasolacrimal duct
-Valve of Hasner
What muscle surrounds the canaliculi?
Muscle of Horner
Canaliculi are ____ mm long.
10
Lacrimal sac location:
lies within fossa formed by maxillary and lacrimal bones
True/false:
Lacrimal fossa is posterior to orbital septum.
False: anterior
Define dacryocytitis.
Infection of lacrimal sac, usually due to obstruction of nasolacrimal duct.
Nasolacrimal duct is about ____ mm.
15
____________ travels adjacent to maxillary sinus through nasolacrimal canal.
Nasolacrimal duct
Nasolacrimal duct terminates in __________.
Inferior meatus
This structure prevents the backflow of nasal fluids:
Valve of Hasner
Name the different types of tear secretion:
- Basal
- Reflex
- Emotional
Basal tear secretion purpose:
Regularly secreted to keep cornea moist and nourished
Basal tear secretion is via which glands?
- Sebaceous glands
- Meibomian glands
- Conjunctiva
Reflex tear secretion serves what purpose?
It is in response to irritants and is secreted rapidly to flush the cornea
Afferent limb of tear reflex arc is innervated by:
CN V1
Efferent limb of tear reflex arc is innervated by:
CN VII
Underlying mechanism is unknown for this type of tear secretion:
Emotional
In CN V lesions, ______ tears are lost but ______ are not.
Reflex; emotional
What are the GA nerves to the eyelids?
- Ophthalmic (CN V1) + frontal and lacrimal branches
- Maxillary (CN V2) + infraorbital and zygomaticofacial branches
Upper lid GA innervation is by:
CN V1
True/false:
CN V2 innervates the lower lid.
True
GE innervation of the eyelids is via:
Zygomatic branchof CN VII to orbicularis oculi
Sympathetic innervation (VE) of the eyelids is by this muscle:
Muller’s muscle
Supraorbital and supratrochlear nerves are branches of:
Frontal nerve of CN V1.
What is the blood supply to the eyelids from the ECA?
- Facial artery
- Maxillary artery
Terminal branch of the facial artery is called _______ and goes to _________.
Angular artery; medial canthus
Maxillary artery branches in _____________, enters the orbit via _____________ as infraorbital artery and supplies ______ and ______.
Infraorbital fossa
IOF
Lower lid and lacrimal sac
Maxillary artery joins these two arteries:
Angular artery (ECA) and dorsal nasal artery (ICA)
What is the blood supply to the eyelids from the ICA?
Ophthalmic artery and it's branches: Lateral palpebral Medial palpebral Dorsal nasal Supraorbital Supratrochlear
What is the venous drainage of the eyelid?
Superior ophthalmic vein
Inferior ophthalmic vein
Infraorbital vein
What is the pathway for venous drainage from superior ophthalmic vein?
Angular + superorbital veins -> superior orbital vein -> cavernous sinus
Inferior ophthalmic vein drains into:
Cavernous sinus OR pterygoid venous plexus
Infraorbital vein drains into:
Pterygoid venous plexus
Name the structure:
tough outer layer of the eyeball that gives the eye rigidity.
Sclera
Define conjunctiva:
Thin vascularized membrane covering sclera
Name the structure:
transparent bulge on the front part of the eye to allow light to enter the eye
Cornea
Define iris:
Colored part of the middle layer of the eye
Name the structure:
Central opening in the iris; diameter altered to control amount of light entering the eye
Pupil
Function of the lens:
Focuses light onto the retina
Properties of the lens:
- Biconvex
- Transparent
- Elastic
- Made of water and proteins
Layers of the lens:
- Capsule: thin outer membrane
- Cortex: soft
- Nucleus: Hard center
Soft layer of the lens is called:
Cortex
Identify the structure:
The anterior 1/6 of the eyeball from cornea to iris.
Aqueous chamber
Name the components of the aqueous chamber of the eye:
- Anterior chamber: anterior to iris
- Posterior chamber: posterior to iris
- Aqueous humor: Clear fluid that nourishes the avascular cornea and lens
What is the vitreous chamber of the eye?
It is the posterior 5/6 of the eyeball from the lens to retina
What are the properties of vitreous body?
- Transparent
- Gelatinous substance that fills the vitreous chamber
- Mainly water and collagen fibers
What does the outer layer/tunic of the eye consist of?
Cornea: transparent fibrous layer
Sclera: opaque layer of dense CT
What does the middle layer of the eye consist of?
Choroid
Ciliary body
Iris
Properties of choroid:
- Highly vascular
- Pigmented
- Between the sclera and retina
Middle layer of the eye is ______ and _____.
Vascular; muscular
Properties of ciliary body:
- Muscular and vascular
- Connected choroid to iris
Identify the structure:
Connects iris to choroid.
Ciliary body
Properties of iris:
- Muscular and vascular
- Pigmented
- Thin
- Contractile diaphragm
- Anterior to lens
What does the inner layer of the eye consist of?
- Retina
- Optic disc
- Macula lutea
Inner most layer of the inner layer of the eye is:
Retina
Properties of the optic disc:
- Oval
- Depressed area in the back of the eye
- Optic nerve enters thru it
Properties of macula lutea:
- Lateral to the optic disc
- Highest concentration of cone photoreceptors for optimal vision
Pathway of light through the refractive media:
- Tear film
- Cornea
- Aqueous humor
- Lens
- Vitreous body
Pathway of light via non-refractive media:
Pupil
What is the nervous pathway of the pupillary light reflex?
Afferent limb: light on retina -> ortic nerve -> brain
Efferent limb: Brainstem -> CN III -> parasympathetic root (Edinger Westphal nucleus) -> ciliary ganglion (synapse) -> Short ciliary nerve -> sphincter pupillae
What is the pupillary light reflex?
When light hits the eye, the pupil automatically constricts
What is the pupillary dark reflex?
In the dark, pupils automatically dilate
What is the nervous pathway of the pupillary dark reflex?
Afferent: absence of light on retina -> optic nerve -> brain
Efferent: brain -> spinal cord -> cervical sympathetic chain -> superior cervical ganglion (synapse) -> internal carotid artery ->
- ophthalmic nerve -> nasociliary nerve -> short ciliary nerve -> dilator pupillae muscle
- Ophthalmic nerve -> nasociliary nerve -> long ciliary nerve -> dilator pupillae
What is the nervous pathway of the corneal touch reflex?
Afferent:
- touch cornea -> short ciliary nerve -> ciliary ganglion (no synapse) -> nasociliary nerve -> ophthalmic nerve -> trigeminal ganglion -> brainstem
- touch cornea -> long ciliary nerve -> nasociliary nerve -> ophthalmic nerve -> trigeminal ganglion -> brainstem
Efferent: Brainstem -> facial nerve -> orbicularis oculi
What is the corneal touch reflex?
When you touch the cornea, you instinctively blink