Neural Communication

1. Structure of the Neuron

Potentials

Resting Potential

• nothing is happening


• gates are closed and the positive ions are on the outside with the negative ions on the inside

Action Potential

• due of stimulation from either heat, chemicals, pressure or light, gates open allowing the positive ions to flow into the neuron


• a brief electric charge is produced, a process called depolarization


• this produces a chain reaction down the axon


• this event can occur up to 100 times a second

Refractory Period

• the positive ions are pumped out
• Neurons can send excitatory or inhibitory messages


• Each neuron has a particular threshold i.e. it fires when the excitatory messages are greater than the inhibitory messages


• All or nothing response i.e. neurons fire or they do not fire


• the speed of firing does not change but the rate of firing can

For those of you who love all of this visit a great site supposedly designed for kids but which I found very challenging. Its called Neuroscience for Kids.

Communication

• neurons fire across a small gap called the synapse
  
• when a message reaches the axon it releases neural transmitters (chemicals) that travel across the synapse
• these chemicals fit like a key into receptor sites on the neighbouring neuron