Right now, lets get the basics sorted.
The neurones that receive impulses from receptor cells are called sensory neurones.
That makes sense doesn't it - the sensory neurone senses things because it is receiving information.
The neuron in the diagram above has lots of dendrites - these are to receive the information. This information is passed along the neurone as an impulse. The impulse travels along the neurone along the axon. Remember, the myelin sheath is a fatty layer that insulates the axon so the impulse moves faster.
It does not protect the axon!
The neurones that take impulses to effectors are called motor neurones.
Effectors are the things that make an effect - they could be the muscles.
Motor neurones do not have a dendron, the dendrites are on the cell body.
Relay neurones are short neurones that join up the motor neurones and the sensory neurones. These neurones are found in the spinal cord and the brain.
Now, so you've got all these neurones joining with each other. Well, there is a bit of a problem. Where the neurones connect with each other there is a small gap called a synapse. Impuses are transmitted across the gaps in synapses by chemicals called neurotransmitters. Stimulants like caffeine speed up the neurotransmission of nerve impuses across the synapses.
The synapse actually slows down the impulse but they are useful because as the chemicals are only released from the axon endings the impulse can only go in one direction. Botox injections stop impulses from the motor neurones reaching the muscle cells. This stops the muscle cells working so the skin doesn't wrinkle.
The reflex arc - learn it!
The reflex arc lets you do things without thinking. The are responses that are very quick and automatic and they protect you. They use neurone pathways called reflex arcs where a sensory neurone directly controls a motor neurone. Reflex arcs bypass the brain so you don't decide what to do. Reflex arcs make you automatically blink if something gets in your eye or makes your pupils in your eyes get smaller in bright light.
The neuron in the diagram above has lots of dendrites - these are to receive the information. This information is passed along the neurone as an impulse. The impulse travels along the neurone along the axon. Remember, the myelin sheath is a fatty layer that insulates the axon so the impulse moves faster.
It does not protect the axon!
The neurones that take impulses to effectors are called motor neurones.
Effectors are the things that make an effect - they could be the muscles.
Motor neurones do not have a dendron, the dendrites are on the cell body.
Relay neurones are short neurones that join up the motor neurones and the sensory neurones. These neurones are found in the spinal cord and the brain.
Now, so you've got all these neurones joining with each other. Well, there is a bit of a problem. Where the neurones connect with each other there is a small gap called a synapse. Impuses are transmitted across the gaps in synapses by chemicals called neurotransmitters. Stimulants like caffeine speed up the neurotransmission of nerve impuses across the synapses.
The synapse actually slows down the impulse but they are useful because as the chemicals are only released from the axon endings the impulse can only go in one direction. Botox injections stop impulses from the motor neurones reaching the muscle cells. This stops the muscle cells working so the skin doesn't wrinkle.
The reflex arc - learn it!
The reflex arc lets you do things without thinking. The are responses that are very quick and automatic and they protect you. They use neurone pathways called reflex arcs where a sensory neurone directly controls a motor neurone. Reflex arcs bypass the brain so you don't decide what to do. Reflex arcs make you automatically blink if something gets in your eye or makes your pupils in your eyes get smaller in bright light.
