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Neurones pass information into and out of the nervous system. As the neurones never touch each other, there is a small gap between them called a synapse.
When an electrical impulse reaches this gap via a neurone, a chemical transmitter is released and activates receptors in another neurone. This generates an electrical signal to be generated in the other neurone. The chemical trigger is then destroyed.

Neurones are specially-adapted cells which carry impulses (electrical signals). Neurones are elongated to make connections between parts of the body and they have branched ending which allows a signal neurone to act on loads of muscle fibres or connect with other neurones. There are three types of neurones.
The sensory neurones take nerve impulses from the receptors to the central nervous system. The relay neurones pass impulses on from the sensory neurones in the central nervous system and the motor neurones take impulses from the central nervous system to the glands or muscles.

The brain coordinates nearly all of the actions of the body.
The frontal lobe controls voluntary movement, verbal expression, problem solving, willpower and planning. The parietal lobe controls touch. The temporal lobes controls taste, smell, hearing, thinking and memory and the occipital lobe controls vision.
It is the most delicate organ in the human body. It instructs and coordinates actions, receives, stores and recalls information. But damage to the brain can happen

• Tumours in the brain are developed when the cells of the brain divide and grow uncontrollably. When a tumour grows large enough, it presses against other parts of the brain causing them to not work probably.
• Parkinson’s disease starts when the brain stops producing dopamine, a chemical that brain cells use to communicate with each other. The lack of dopamine means that the brain cannot coordinate the movements properly (among other things).
• Strokes are when part of the brain is starved of oxygen and cannot work properly. If the part of your brain which controls speech is damaged, the sufferer will not be able to speak well after the stroke
• Grand mal epilepsy is when the brain sends out uncoordinated instructions to the body, creating epileptic fits. Brain neurones communicate with each other by sending electrical impulses

The brain, the spinal cord, and paired nerves and receptors (sense organs) make up the nervous system. The spinal cord and the brain are referred to as the CNS or the central nervous system. The peripheral nervous system is the rest of the nerves in the body.
The nervous system allows organisms to coordinate their behaviour and react to their surroundings. Humans have five main senses (Ten if we focus on all of them). Receptors in the sense organs detect external and internal changes, which allow us to respond to these stimuli

• Sight
• Hearing
• Taste
• Smell
• Touch

Information from the receptors passes along the neurones to the brain, which coordinates the response to the stimuli.

The nervous system starts with a receptor, which passes the messages along to the sensory neurones. The message is passed along to the central nervous system. First the relay neurones, then the spinal cord, and brain. Then finally it reaches the motor neurones.