Eye Flashcards
Eyelids Name
Palpebrae
Sclera
“Whites” of the eyes
Cornea
Transparent enter part in front of Iris
Iris
Pigmented part of the eye
Pupil
Opening in the Iris
Conjunctive Definition
Lining sclera and eyelid
Conjunctiva Function
Secrete mucus as lubricant for eyes/eyelids
Lacrimal Apparatus Function
Produces/Collects tears (Lacrimal Fluid)
Lacrimal Gland
Produces and secretes tears
Eye Fluid
Fluid is swept across the surface of the eye by the eyelids. Goes from lateral to medial
Lacrimal Canaliculi
From Lacrimal Duncti to Nasalacrimal Duct
Nasolacrimal Duct
Drains tears into nasal cavity, where they are eventually swallowed
When a person cries, tears spill onto the cheek and person gets a runny nose. What is happening?
Tears flood lacrimal duct
Lacrimal duncti can’t collect all of the tears
Medial Rectus
Moves eye medially (Adducts)
Looking into middle of body
Lateral Rectus
Moves eye laterally (Abducts eye)
Away from body, looking out
Superior Rectus
Elevates eye and moves eye medially (Adducts Eye)
Look Up
Inferior Rectus
Depresses eye and moves eye medially
Looking Down
Superior Oblique
(Between Superior and Medial)
Depresses eye and moves eye laterally
Inferior Oblique
Elevates eye and moves eye laterally
Lens Definition
Biconvex, transparent structure inside eyeball
Lens Function
Changes shape (flat or rounded) to focus light rays
Lens held in place by?
Suspensory Ligaments
More rounded when looking closely at an object, flattened when looking far away
3 Eyeball Layers
Fibrous (External) Tunic
Vascular tunic
Retina
Fibrous (External) Tunic
It is avascular
Fibrous Tunic Components
Sclera
Cornea
Fibrous Tunic; Sclera
Posterior 5/6 of eye
Fibrous Tunic; Sclera Function
To provide shape to the eyeball and protect inner parts
Fibrous Tunic; Cornea
Curved, transparent structure anterior to Iris and Pupil
Anterior 1/6 of eye
Fibrous Tunic; Cornea Function
Admits and refracts (bends) light
Laser Vision Correction
Laser removes some cells from the middle part of the cornea to change its shape so that it can let in more light
Vascular Tunic Components
Choroid
Ciliary Body
Iris
Vascular Tunic; Choroid
Dark brown membrane
Vascular Tunic; Choroid Function
Contains many tine blood vessels that help nourish the retina
Vascular Tunic; Ciliary Body
A ring of smooth muscle tissue that surrounds the lens.
Attaches to lens via suspensory ligaments
Vascular Tunic; Ciliary Body Functions
- As the smooth muscle contracts, suspensory ligaments relax to make the lens more round
- Produces Aqueous Humor
Vascular Tunic; Iris
Pigmented, colored part of eye
Pupil
Vascular Tunic; Iris Function
Regulates the amount of light entering eye (by enlarging [dilating] or narrowing [constricting])
Retina Components
Pigmented Layer
Neural Layer
Retina
Posterior 3/4 Of eye
Retina; Pigmented Layer
Outer layer Adjacent to choroid
Retina; Pigmented Layer Function
Absorbs excess light to prevent reflection/glare
Provides Vitamin A to neural layer
Retina; Neural Layer
Inner Layer
Retina; Neural Layer Functions
Its photoreceptors receive light information and convert it into nerve impulses that are sent via CN II (Optic Nerve) to the brain
Two Types of Photoreceptors
Rods
Cones
Rods Definition
Low Light, only see Black and White
Cones Definition
Require more light, but these let you see in color
Optic Disc (“Blind Spot”)
Area where the optic nerve exits the eye.
Contains no photo receptors
Can’t detect light at that spot, taking information to brain from eye
Macula Lutea
Lateral to the optic disc
Fovea Centralis
In the center of Macula Lutea
Contains sharpest vision (Only Cones)
Detached Retina
Fluid collects between the pigmented layer and the neural layer of the retina. (Cuts off photoreceptors from their blood supply and source of Vitamin A) Retina needs Vitamin A to function
Internal Chambers of the Eye
Anterior Cavity
Posterior Cavity
Anterior Cavity
Between Cornea and Lens
Filled with Aqueous Humor
Aqueous Humor
Supplies nutrients and removes waste for lens and Cornea; Continually being produced and wasted
Posterior Cavity
Between Lens and Retina
Contains Vitreous Humor
Vitreous Humor
Helps maintains shape of eye and keeps retina against choroid. This is not continually produced (This jelly substance only produced once at birth; Reason for big eyes in children)