Eye Lid and Eyeball Flashcards
Parts of the Eye
Palpebrae (Eyeball)
Lacrimal Apparatus
Eyeball
Palpebrae
What are the Eyelids?
2 skin folds Anterior to Eyeball
Palpebrae
What separates the Eyelids?
Transverse Palpebral Fissure
Space which exists between the two open eyelids
Palpebrae Lining
Inner surface lined with …
Palpebral Conjunctiva
Palpebrae: Lining
Palpebral Conjunctiva reflects onto sclera to become …
Bulbar Conjunctiva
Palpebrae: Lining
Reflection of Palpebral to Bulbar Conjunctiva is …
Conjunctival Fornix
Palpebrae: Lining
What is formed when the eyelids are closed?
Conjunctiva forms a closed sac
Palpebrae
Components
Palpebral Part of Orbicularis Oculi Muscle
Levator Palpebrae Superioris Muscle
Tarsal Muscle
Tarsal Plates
Orbital Septum
Palpebrae: Components
What are Tarsal Plates?
Thin Fibrous Plates in the Eyelid
Palpebrae: Components
Where are Tarsal Plates attached?
Margins of Orbit by Orbital Septum
Palpebrae: Components
Which glands open into the Margins of the Eyelids?
Tarsal Glands (Modified Sebaceous Glands)
Palpebrae: Components
Purpose of Tarsal Plates
Support Eyelid
Maintain Eyelid Shape
Lacrimal Apparatus
Components
Lacrimal Gland
Conjunctival Sac
Lacrimal Puncta
Lacrimal Canaliculi
Lacrimal Sac
Nasolacrimal Duct
Lacrimal Apparatus
Location of Lacrimal Sac
Lacrimal Groove
Lacrimal Apparatus
Nasolacrimal Duct opens into …
Inferior Meatus
Lacrimal Apparatus
Lacrimal Gland location
Lacrimal Fossa in Frontal Bone
Lacrimal Apparatus
Lacrimal Gland secretes …
tears into superior fornix of conjunctival sac
Lacrimal Apparatus
Function of Lacrimal Gland
Nourishes Avascular Cornea
Washes away irritants
Keeps Cornea moist
Contains Antibacterial Enzymes
Lacrimal Apparatus
Secretomotor Pathway
Eyeball
Layers
Outer to Inner:
Fibrous Layer
Vascular Layer
Nervous Layer
Eyeball: Fibrous Layer
Anterior part formed from …
Transparent Cornea (1/6th of Fibrous Layer)
Eyeball: Fibrous Layer
Posterior part formed from …
White Sclera (5/6th of Fibrous Layer)
Eyeball: Vascular Layer
Characteristics
Pigmented Layer
Eyeball: Vascular Layer
Components
Iris
Cilliary Body
Choroid
Eyeball: Nervous Layer
Formed from …
retina
Eyeball: Nervous Layer
Retina contains …
visual receptors
Eyeball: Cornea
Shape
Convex
Enables Refraction and Transmission of Light
Eyeball: Cornea
How is the Cornea transparent?
Specialised arrangement of Collagen Fibrils kept relatively dehydrated
Eyeball: Cornea
Components of Cornea
Outer Epithelium
Nonvascular Collagen Stroma
Non-replicating Endothelial Monolayer
Eyeball: Cornea
Conditions affecting the Cornea
Nebula
Leucoma
Eyeball: Cornea
Cause of Nebula
Superficial Scars in Bowmans Layer and Superficial Stroma
Eyeball: Cornea
Effects of Nebula
Blurred Vision
Irregular Astigmatism
Eyeball: Cornea
Cause of Leucoma
Scarring of more than half of Corneal Stroma
Eyeball: Cornea
What is Adherent Leucoma?
Healing after perforation of cornea with incarceration of iris
Eyeball: Sclera
Characteristics
Opaque
Maintains eyeball shape
Eyeball: Sclera
Sclera is thick throughout except at the …
Sclerocorneal Junction (Limbus)
Entrance of Optic Nerve (Lamina Cribrosa)
Eyeball: Sclera
Anterior Surface
Covered by Conjunctiva
Eyeball: Sclera
Posterior Surface
Covered with Tenon’s Capsule
Eyeball: Sclera
Canal of Schlemm/Scleral Venous Sinus location
Posterior Part of Corneoscleral Junction
Eyeball: Sclera
Function of Canal of Schlemm
Collect Aqueous Humor and deliver it to Eyeball Veins
Eyeball: Iris and Pupil
What is the Iris?
Thin, Contractile, Pigmented Diaphragm
Eyeball: Iris and Pupil
What is the Pupil?
Central Aperture in Iris
Eyeball: Iris and Pupil
Peripheral attachment of Iris
Anterior Part of Cilliary Body
Eyeball: Iris and Pupil
Iris and Pupil separate the ____ from the ____
__anterior chamber__
__posterior chamber__
Eyeball: Iris and Pupil
Muscles
Sphincter Pupillae (Parasympathetic)
Dilator Pupillae (Sympathetic)
Eyeball: Iris and Pupil
Circular Muscles of Iris contracted …
Constricted Pupil
Eyeball: Iris and Pupil
Radial Muscles of Iris contracted …
Dilated Pupil
Eyeball: Ciliary Body
Ciliary Body shape
Triangular
Eyeball: Ciliary Body
Continuous anteriorly with …
iris
Eyeball: Ciliary Body
Continuous posteriorly with …
choroid
Eyeball: Ciliary Body
Name of Anterior Part
Ciliary Processes
Eyeball: Ciliary Body
What do the Ciliary Processes give attachment to?
Suspensory Ligaments of Lens
Eyeball: Ciliary Body
What does the Scleral Part have?
Ciliary Muscles
Eyeball: Ciliary Body
Which nerve supplies the Ciliary Body?
Parasympathetic Nerve supply from Edinger-Westphal Nucleus
Eyeball: Choroid
What is the Choroid?
Pigmented Layer
Eyeball: Choroid
What two structures does the Choroid separate?
Sclera and Retina
Eyeball: Choroid
Choroid is loosely attached to …
sclera
Eyeball: Choroid
Choroid is firmly attached to …
retina
Eyeball: Choroid
What perforates the Choroid posteriorly?
Optic Nerve
Eyeball: Choroid
What are the layers of the Choroid?
Outer Layer (Large Blood Vessels)
Middle Layer (Blood Capillaries)
Inner Layer (Basal Lamina)
Eyeball
Chambers of Eye
Anterior Chamber
Posterior Chamber
Vitreous Chamber
Eyeball: Chambers
Anterior Chamber location
Between Cornea and Iris
Eyeball: Chambers
Posterior Chamber location
Between Iris, Lens and Ciliary Processes
Eyeball: Chambers
How do the Anterior and Posterior Chamber communicate with each other?
Through Pupil of Iris
Eyeball: Chambers
What do the Anterior and Posterior Chambers contain?
Aqueous Humor (fluid)
Schlemm’s Canal collects Aqeuous Humor and delivers it to Veins of Eyeball
Eyeball: Chambers
What is Aqueous Humor?
Clear Fluid which fills the Anterior and Posterior Chambers
Eyeball: Chambers
Where is Aqueous Humor secreted from?
Ciliary Processes
Eyeball: Chambers
Function of Aqueous Humor
Maintains eye shape by exerting internal pressure
Eyeball: Chambers
What does obstruction of Canal of Schlemm cause?
Glaucoma
Eyeball: Chambers
Location of Vitreous Chamber
Posterior to Lens and Ciliary Processes
Eyeball: Chambers
Vitreous Chamber contains …
gelatinous transparent vitreous body
Eyeball: Chambers
How is the Gelatinous Transparent Vitreous Body produced
Cells of Ciliary Body
Eyeball: Chambers
Function of Gelatinous Transparent Vitreous Body
Keeps Retina in place by pressing it against the Choroid
Eyeball: Lens
Characteristics
Transparent
Biconcave
Enclosed in Transparent Capsule
Eyeball: Lens
Components of Transparent Capsule
Capsule
Epithelium
Fibers
Eyeball: Lens
Relations
Anterior: Iris
Posterior: Vitreous Body
Eyeball: Lens
How is it suspended?
Suspended from Cilliary Processes by Suspensory Ligaments
Eyeball: Lens
Function
Refracts light
Accommodation
Eyeball: Lens
What is Accommodation?
Increasing convexity of lens for near vision
Decreasing convexity for far vision
Eyeball: Lens
Medical Condition affecting Lens
Cataract - Lens proteins break down making it cloudy
Eyeball: Retina
Structure of Retina
Outer Pigmented Layer
Inner Nervous Layer
Eyeball: Retina
Outer Surface attached to …
choroid
Eyeball: Retina
Inner Surface attached to …
vitreous body
Eyeball: Retina
Anterior edge is called …
ora serrata
Eyeball: Retina
What are the receptors?
Rods
Cones
Eyeball: Retina
Ganglion cells gives rise to …
Optic Nerve
Eyeball: Optic Disc
Location
Posterior Retina
Eyeball: Optic Disc
What is the Optic Disc?
Where Ganglion Cell axons converge to leave the eye as Optic Nerve
Eyeball: Optic Disc
Why can light which hits the Optic Disc not be seen?
No Visual Receptors
Eyeball: Optic Disc
Pierced by …
central artery and vein
Eyeball: Macula Lutea
What is the Macula Lutea?
Yellow Spot Lateral to Optic Disc
Eyeball: Macula Lutea
Depression in the centre of the Macula Lutea is the …
fovea centralis
Eyeball: Macula Lutea
The Macula Lutea is the area of …
maximum visual acuity
Eyeball: Macula Lutea
What type of receptor cell does the Macula Lutea have?
Cones
Eyeball: Papilledema
What is Papilledema?
Swelling of the Optic Disk
Eyeball: Papilledema
What Causes Papilledema?
Blood Supply of Eye
Internal Carotid Artery → Ophthalmic Artery → Internal Carotid Artery
What is Myopia?
Distant Objects out of focus because light converges in front of retina
What is Hypermetropia/Hyperopia?
Near Objects out of focus because light converges behind the retina
What is Presbyopia?
Lenses become harder making it more difficult to focus on nearby objects
Causes of Retinal Detachment?
Trauma to the eye
Symptoms of Retinal Detachment
Flashes of light
Appearance of floaters
Curtain like shadow over visual field
