Coordintion and Control

Co-ordination and Control

Responding to Change

The nervous system allows humans to react to their surroundings and coordinates behaviour.

The nervous system has receptors that detect Stimuli.

Electrical impulses pass to the brain along neurones.

The brain coordinates responses.

The brain and spinal chord forms the central nervous system.

Nerves contain neurones.  Sensory neurones carry impulses from receptors to the central nervous system.

Motor Neurones carry impulses from the central nervous system to effector organs which could be muscles or glands, the muscles contract and glands release chemicals.

Hormones are chemicals that keep the body controlled and coordinated.

Reflex Actions

Some responses to stimuli are automatic and rapid and are called reflex actions.

Reflex actions run everyday bodily functions and help you to avoid danger.

Reflex actions invole 3 types of neurones.  Sensory neurones, motor neurones and relay neurones which connect sensory neurones and motor neurones.  Usually found in the central nervous system.

Junctions between nerves are called synapses.

Most reflex actions are as follows: Stimulus, receptor, co-ordinator, effector, response.

A receptor- detects a stimulus.

A sensory neurone- transmits an impuls to the central nervous system.

A relay neurone- passes the impulse on.

A motor neurone- is…