Reflexes Help Prevent Injury
- It is an automatic response to certain stimuli - reduces the chances of being injured.
- The route taken by the information in a reflex /9 from receptor to effector) is called a Reflex Arc.
- The neurones in reflex arcs go through the spinal cord or through an unconscious part of the Brain
The Reflex Arc goes through the Central Nervous System
- When a stimulus is detected by receptors, an impulse is sent along the sensory neurone to the CNS.
- In the CNS the sensory neurone passes on a message to another neurone which is the Relay. There is a gap between neurones called the Synapses and pass along chemical messages.
- Relay neurones relay impulse to the motor neurone.
- The impulse then travels along it to the effectors which make your muscles contract.
- The Cornea bends light into the eye.
- The Iris controls the diameter of the Pupil
- The Lens focuses the light onto the Retina.
- The Retina contains rods and cones. Cones sense colours, Rods don't.