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Nerve Cells & Neurotransmission. The Brain :. Made up of millions of nerve cells called neurons. Neuron contains 3 Parts:. Dendrites:. Receive message. Axon. Transmits messages from the cell body to other dendrites or body tissues (muscles). Cell Body.
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The Brain: • Made up of millions of nerve cells called neurons
Dendrites: • Receive message
Axon • Transmits messages from the cell body to other dendrites or body tissues (muscles)
Cell Body • Directs all activities of the neuron
Neurotransmission • Transfer of a message from the axon of 1 nerve cell to the dendrites of another. • Does not have direct contact
Communication between nerve cells: • Occurs through the release of chemical substances (neurotransmitters) into the space between the axon & dendrite (synapse)
When Neurons communicate: • A message (electrical impulse) travels down the axon to the synapse • This triggers the release of neurotransmitters into the synapse
Neurotransmitters (chemical messengers) • Diffuse across the synapse • Bind to receptors • This stimulates (starts) or inhibits (stops) an electrical impulse in the receiving neuron’s dendrites.
Neurotransmitters • Very specific • Like a lock & key • Reusable
Myelin: • Fatty substance • Covers axons • Increases rate of conduction (how fast the message travels) • 120 meters/second verses 2 meters/second