the human nervous system

What does the nervous system do

Allow us to react to our surroundings, and coordinate actions in response to a stimuli

Usual response to a stimuli

Receptor cells convert a stimulus into an electrical impulse

This electrical impulse traveled along cells called sensory neurones to the central nervous system

Here the information is processed and the appropriate repsonse is coordinated, resulting in an electrical impulse being sent along motor neurones to effectors

The effectors carry out a response

What are reflexes and why are they important

Automatic responses which take place before you have time to think

Important as they prevent the individual from getting hurt

Where does the information travel during a reflex

Down a pathway called a reflex arc, allowing vital responses to take place quickly

How is this reflex arc pathway different from the usual response

The impulse does not pass through the conscious areas of your brain

Examples of reflex arcs

Pupils getting smaller to avoid damage from bright lights

Moving your hand from a hot surface to avoid damage

What is a synapse

A gap between two neurones

Describe what happens at synapses

When the impulse reaches the end of the first neuron, a chemical is released into the synapse

The chemical diffuses across the synapse

When the chemical reaches the second neuron it triggers the impulse to begin again in the next neuron

What is reaction time

Time taken to respond to a stimulus