A neuron is a very specialized cell that forms the basis of the nervous system. It is also referred to as a nerve cells. Neurons are unique in that they transmit signals throughout the body. These signals are referred to as action potentials, nerve impulses or spikes.
Lets make this very practical. If you need to send a signal very quickly to a part of the body, the neuron is the cell for the job. Your brain needs to tell your hand to move? It sends that signal via neurons. You touch a hot stove, the signal needs to go to your brain quickly, so that you can realize that it hurts and pull your hand away before you do some serious damage, neurons send that signal faster than you can say OUCH!
The parts of a neuron:
- Dendrites: these are the points of connections between neurons (synaptic connections). When a connection is made with the soma of another cell (as opposed to another dendrite), this is a stronger connection.
- Soma: The cell body of a neuron. This is the part of the neuron that is most like other cells. It has the nucleus, genetic machinery and is where many of the metabolic processes happen.
- Axon: This is where the magic happens. The Axon has a base where it is continuous with the soma. This swollen section is called the axon hillock, or the “spike” initiating zone (where the nerve impulse originates). The nerve impulse then travels down the axon to the Axon Terminals.
- Axon Terminals: These are the ends of axons. They contain neurotransmitters. When the nerve impulse reaches the axon terminals, the axon terminals release the neurotransmitter, which may then result in an action potential in the next cell.
There are three basic types of neurons: Sensory neurons, motor neurons and interneurons. Sensory neurons bring signals to the central nervous system (CNS) and Motor neurons send signals from the CNS to the rest of the body. Interneurons are in the CNS and allow the sensory neurons to communicate with the motor neurons.
The take home message is that neurons are what it’s all about in the nervous system.