Lesson Notes

Lesson 2.1a What Is a Neuron? Psychology at the Micro Level

The basic parts of a neuron include the dendrites, soma (cell body), axons, and terminal buttons. How do these messages get relayed through the body? Well, in order to understand how this is done, you will need to understand the process known as an action potential. You’ll learn how the myelin sheath that covers many neurons can send a message to the brain at a speed of 100 meters per second! Click on neuron for a visual display.

Lesson 2.1b  How Do Neurons Communicate? An Electrical and Chemical Language

Communication within a neuron follows the process known as an action potential. This is where the message is sent down the axon as a neural impulse. Look at Figure 2.2 on page 56 and notice the process of a message being sent through the neuron as the axon goes from resting potential (depolarized) state to a action potential (polarized) state.

So what happens when a message gets to the end of a neuron? At this point, a neurotransmitter gets released into the synapse from the terminal buttons and attaches itself to a welcoming neuron’s dendrites…and the process continues from there.

We have many different neurotransmitters emitted by our body. Depending on the type of neurotransmitter released will depend on how our body will react. For example, people who do not get enough serotonin released into their body can feel disturbed sleep patters, lack of motivation, and a loss of appetite – all symptoms usually associated with feelings of Depression.

Besides naturally producing neurotransmitters in our bodies, people sometimes ingest chemicals that either mimic (agonist) or inhibit (antagonist) neural messages from being delivered to our brain or nervous system. For example, morphine can mimic endorphins which control our experience of feeling pain, especially when you are badly hurt.

The other communication system in our body is the Endocrine System which releases hormones into our bodies. Some of these hormones control our growth, our sex drives, and the “fight or flight” response when we are faced with danger.