B9.2 and B9.3 - The Eye and Hormones Flashcards
List the structures of the eye. [9]
Cornea
Iris
Pupil
Lens
Retina
Optic nerve
Ciliary muscles
Suspensory ligaments
Blind spot
What is the function of the cornea and where is it located?
To refract light. It is the transparent outer layer found at the front of the eye.
What is the function and of the iris?
To control how much light enters the pupil through contracting and relaxing the muscles.
What sort of organ is the eye?
Sense organ.
What are sense organs?
Groups of receptor cells that respons to specific stimuli.
What is the lens?
It is a large disc that changes shape to focus light on the retina.
What is the optic nerve?
A nerve that carries impulses from the receptors on the retina to the brain.
What is the area where the optic nerve located called and why?
The blind spot because there aren’t any light receptors.
What is the fovea?
A dip in the back on the retina that contains cones.
What are rods?
- Found in peripheral part of retina
- Very sensitive to light (work well in dim light)
- Gives info in black and white
What are cones?
- Mainly found in the fovea
- Less sensitive to light
- Three types which give info in red, green, and blue
What is the vitreous humour?
Jelly-like fluid in rear chamber of eye that maintains eye shape.
What are the suspensory ligaments?
Attach lens to ciliary body.
What is the pupil?
Circular opening for directing light to the lens.
What are the ciliary muscles.
Contains circular muscles that alter the shape of the lens during focusing.
