THE EYE Flashcards
Sclera
- Outer white part of eye
- Tough protection
- Maintains eye shape
Cornea
- protection
- outermost lens
- bends/focuses entry of light into eye
- does not receive blood only oxygen nutrients
Iris
- regulates amount of light that passes through the pupil to retina/inner eye
- thin circular muscles act as diaphragm to control pupil size
- controls pupil size
Pupil
Opening for light to enter inner eye
Lens
Changes shape to focus on objects at different distances
Choroid
•nourish outer layer of retina
Retina
- Lines back of inner eye
- site of all receptors
- translates light stimulus into nerve impulse for visual recognition in brain
Fovea centralis
- small pit on the retina
- only has cones
- most acute/sharp vision takes place here
Suspensory ligaments
- Muscle connecting lens and ciliary body
* Adjusts shape of lens to increase/decrease light refraction
Ciliary body/muscle
- holds lens in place
* helps to adjust lens shape
Optic disk/Blind spot
- Beginning point of optic nerve
- entry point for nerve cells and retina blood vessels
- absence of cones/rods=blind spot
Optic nerve
Made up of blood vessels and nerve cells
•transfers retinal visual stimuli through nerve cells to brain
Posterior chamber
- filled with aqueous humor
- maintains pressure in eye
•flows from PC through pupil to AC
Anterior chamber
- filled with aqueous humor
* maintains pressure in eye
Aqueous humor
Watery fluid that maintains pressure needed to inflate eye
Vitreous body
- The open space between the lens and retina
* Filled with vitreous humor
Vitreous humor
- Fills vitreous body with clear gel
- maintains shape of eye
- must be clear enough for visual data to be processed through
Conjunctiva
- Thin membrane that covers sclera and inner eyelid
* for protection and lubrication
Lateral rectus muscle
One of 6 muscles that controls eye movement
•moves pupil from midline
•abductions
Medial rectus muscle
One of 6 muscles that controls eye movement
•moves pupil from midline
•up/down side/side
Cone cells
- for colour vision
* bright lights
Rod cells
- for colour vision
* dim light
