Co-ordination and Response Flashcards
Rods and Cones
Light sensitive receptors which turn light energy into impulses
Cornea
Transparent part at the front of the eye - focuses light
Optical Nerve
Contains sensory neurones which take impulses from the retina to the brain
Iris
Coloured ring containing muscles, surround the pupil
Choroid
Dark layer underneath sclera, prevents light from being reflected around the interior of the eye
Pupil
Hole at the front of the eye - lets light through
Ciliary Muscle
Muscles which adjust the shape of the lens
Fovea
Site on the retina with lots of cones - so we can see most clearly here
Sclera
Tough, white outer coat - acts as protection
Retina
Site of rods and cones at the back of the eye
Lens
Transparent layer which can move to change shape - this focuses light
Blind spot
Where the optic nerve and retina meet - no light sensitive cells
Why do you not have an obvious blind spot in your vision
Your brain is clever and can fill in the gaps by relying of information from both eyes
What muscles are used in the Iris Reflex
Radial muscle
Circular muscle
In dim light what does the Iris Reflex do?
Circular muscle = relax
Radial muscle = contract
Iris size =Thin
Pupil size = wide
How to remember the Iris Reflex - mnemonic and what it stands for
Dude - condition- dim
Relax - relax - circular muscle
Can’t - contract - radial muscle
Think - thin - Iris size
Well - wide - Pupil size
bright is all different
Bea
Can’t
Relax
With
That
What muscle is used in the Accommodation reflex
Ciliary Muscle
These act on the suspensory ligament
How does your eye focus on a far away object
Ciliary Muscle = relax
Suspensory Ligament = taut
Lens shape = thin/flattened
How does your eye focus on a near object
Ciliary Muscle = contract
Suspensory Ligament = slack
Lens Shape = thick/more convex
