The Mammalian Eye Flashcards
Sclera
Fibrous layer that protects the eyeball and allows for attachment of external muscles
Choroid
Vascular pigmented layer which absorbs light and prevent internal reflection
Retina
Photoreceptors layer containing rods and cones
Fovea
Region of retina only containing only cones with lots of photoreceptors
Optic nerve
Transmits impulses to the brain
Blind spot
Region of retina lacking both rods and cones
Vitreous humour
Jelly like fluid in the chamber of the eye that maintains the shape of the eyeball
Ciliary body
Contains circular muscle that alter the shape of the lens during focusing
Iris
Controls the size of the pupil
Pupil
Circular opening for directing light to the lens
Cornea
Transparent portion of sclera across which the greatest refraction of light occurs
Conjunctiva
Membrane that lines the eyelids and protects the cornea
Aqueous humour
Watery fluid that fills the anterior chamber of the eye
Suspensory ligaments
Attach the lens to the ciliary body
Explain how we see (4)
1.light is focused onto retina by the lens 2. Light is absorbed by pigments in the photoreceptors 3. Causes sim of the sodium ion channels to open (generator potential) 4. If threshold is reached,-action potential- bipolar neurone-optic nerve-brain