There are 3 types of neurons: Sensory neuron, motor neuron, and inter-neurons.
Neuron have several parts: the cell body, the dendrites, and the axon. The cell body is the largest volume section, the dendrites conduct messages towards the cells and carry incoming messages, and the axon conduct messages away from the body to send to the next cell in the chain.
An inactive neuron is polarized. It has negative ions (potassium) outside the membrane, and positive ions (sodium) inside. Resting potential is the electrical difference across the membrane of the neuron. Action potential is a brief electrical charge that travels down the axon. It moves sodium ions outside the cell and potassium inside during action potential. The number of Na+ ions moved outside.
Depolarization: Incoming messages that stimulate sections of the axon, and channels in the membrane open that allow Na+ ions to enter the axon.
Repolarization: Then, channels open that allow K+ ions to flow out of the axon, allowing the next depolarization.
The synapse is terminal or the axon where a gap releases the charges to the next transmitter. The synapse is composed of several parts: The tips of the terminal branches of the axon, tiny spaces between the neurons, and receptors.
The synapse is the space between the presynaptic membrane of the axon and the post synaptic membrane of the dendrite. The action potential stimulates the release of neurotransmitters from synaptic vesicles in the axon terminal. The receptor that the neurotransmitter binds to dictates whether it is inhibitory or excitatory. The charge must reach a certain threshold in order for it to be one or the other.