the eye Flashcards
properties, structures and functions
what is a synapse?
where 2 neurons (nerve cells) join together
what is the function of the cornea?
it refracts light and protects the eye
what is the function of the lens?
it focuses the light onto the retina and focusing on objects
what is the function of the iris?
it controls the amount of light entering the eye
what is the function of the fovea?
it gives sharp central vision and light is focused onto this spot by the lens
what forms the optic nerve?
axons of the ganglion cells weave together to form the optic nerve
what is the function of the optic nerve?
It leads to the back of the eyeball and carries impulses to the thalamus and the brains visual corta
rod properties
light sensitive/functions in the dark
have single pigment called rhodopsin which cannot detect colour
connection with the optic nerve
cone properties
higher intensity than rods
contain photo pigments called iodopsin which detects colour
high level of visual sharpness
connection with the optic nerve
which two proteins is rhodopsin broken down into? (this is also known as bleaching)
Opsin and Retinal
Rhodopsin is regenerated slowly, what provides information when rhodopsin is unable to effectively regenerate?
Cone cells act as a backup whilst Rhodopsin is being regenerated
State the photoreceptors in the eye
Rod cells and cone cells
where is light focused as it enters the eye?
the lens/retina
What is the structure of the Sclera?
The white part of the eye, made of tough collagen fibres
What is the structure of the choroid?
Layer of blood vessels that contain a black pigment
What is the function of the choroid?
Absorbs as much light as possible and nourishes the eye
What is the structure of the iris?
a ring of muscle
What is the function of the iris?
controls the amount of light entering the eye
Pupil structure and function?
hole in the iris
allows light to enter the eye
Ciliary body function?
alters shape of lens and produces aqueous humor
Aqueous humor structure and function?
behind the cornea, provides shape and nutrients
Lateral rectus structure and function?
found on the lateral side of the eye and helps orient the pupil away from the body
Medial rectus muscles structure and function?
found in the medial part of the eye
What is the optic disc?
blindspot, no photoreceptors
Why do we have the optic disc?
Its where the optic nerve leaves the eye
What helps animals see in the dark?
The tapetum lucidum
What does the tapetum lucidum do?
It refracts light back through the retina
