Dilation and contraction

Cards (14)

Iris function
Controls diameter of pupil
what does the function of the iris allow in the eye
control amount of light hitting retina
What are the antagonistic pair of muscles in the eye
circular muscles
Radial muscles
what do circular muscles allow the pupil to do
Constrict
What do radial muscles allow the pupil to do
Dilate
How does a pupil dilate in reference to radial and circular muscles
Radial contracts and circular relaxes
How does the pupil contact in relation to radial and circular muscles
Radial relaxed and circular contracts
When a bright light is held at the eye, what following events occur
Bright light > light receptor in eye > sensory neurone > CNS > motor neurone > circular muscles
When a low light is held at the eye, what following events occur
Low light > light receptor in eye > sensory neurone > CNS > motor neurone > radial muscle in iris
What happens to the pupil when circular muscles contract
Pupils constrict
When pupils constrict what is limited and what can this cause
Amount of light entering eye preventing damage to retina
What happens to the pupils when radial muscles contract
Pupils dilate
When pupils dilate what can this maximise and therefore improve
Maximise amount of light entering eye improving vision
What can pupil reflex occur in both eyes even if one eye Is blocked
Multiple synapses are on both sides of the brain which are responsible for pupil reflex