An axon and synapse are both parts of the nervous system of the body. The axon is one end of a nerve cell, while the synaptic gap refers to a space between nerve cells, and the outside of the neighboring nerve cell is its membrane. Although electrical impulses carry information through nerves, when the nerves need to communicate with each other they pass chemicals from one nerve to another. A synaptic gap is the gap that this chemical message travels through to get to another nerve, and the entire collection of axon, gap and receiving cell membrane is the synapse.
The nervous system of the body transmits sensory information to the brain and it also transmits information to parts of the body. It contains two major types of cells, which are the glia and the neurons. Glia are cells that play no important role in information transfer, but rather help the neurons to transmit information efficiently, as structural support and through other roles.
Neurons are those cells that send information to the brain and the body. Each neuron has three main parts. The soma is the central part that contains the genetic material of the cell. Dendrites are the branch-like protrusions from the end of the neuron. Incoming information comes through the ends of the dendrites.
A neuron also has one branch out from the cell that acts as the exit point for information. This is the axon. Axons can be much longer than the dendrites, and they all have distinctive axon endings. In the field of neuroscience, axon endings are also known as boutons, axon feet or synaptic knobs.
Basically, once a neuron receives information through a dendrite, the information passes through the cell and out to another neuron through the axon and synapse. Inside the cell, the information is in the form of electrical impulses. Between neurons, however, the message is chemical in form.
This occurs because once the electrical impulse reaches the axon end of the first neuron, it tells the axon to produce chemicals called neurotransmitters. The axon sends these chemicals into the synpatic gap between it and the next neuron. When these neurotransmitters reach the cell membrane of the next neuron, receptors in the membrane can recognize them.
These membrane receptors, once the neurotransmitter has bound to them, tell the neuron to produce an internal electrical impulse. This impulse travels through the neuron, and out through the axon and synapse between the cell and the next neuron. As this process technically begins at an axon, in the case of an axon and synapse, the axon is presynaptic. This conversion from electrical information to chemical information occurs with all neurons, and is the basic mechanism of the nervous system.
