The nevous system

The nerous sytem enables us to react to our surrounding and co-ordinate our behaviuor. The nerous system ismade up of the brain, spinal cord and nerves.the brain and spinal cord make up the central nervous system (CNS). the CNS co-ordinates responses. The nerves make up theperipheral nervous system. Imformation travels to and from the brain and spinal cord as fast moving electrical impulses along nerve.

Sense organs enables us to detect changes in our surrounding (called stimuli).Sense organs have special cells called receptors that detect changes around us.

Stimulus- a change in our surroundings

Receptors- cells in ou sense organs that detect changes in our surrounding

sensory neurone- nerve that carries impulses from sense organs to the CNS

CNS- co-ordinates the response

Motor neurone- nerve that carries messages to effector

Effector- muscles or glands which bring about an action

Response- is a way of reacting to the stimulus

A reflect arc is a quick automatic response to a stimulus e.g. sitting on a pin, touching a hot object. They protect us.

A reflec arc shows the pathway of impulses to bring about an action

A synapses is the gab between two nerves

1. Impulses get to the end of the neurone

2. Veccicles make chemical transmitters

3. chemicals diffuses across the gap

4.it starts off a new impulsein the next neurone