Neurons are cells that transmit information to other nerve cells, muscle, or gland cells. There are three types of neurons; motor neurons, sensory neurons, and interneurons. Each neuron is composed of a cell body, dendrites, and an axon. Some neurons however have myelin sheath. The cell body supports the life of the neuron, while the axon transmits and carries signals to other neurons. The dendrites are then there to receive those signals. The myelin sheath function is to improve the safety and speed of the neural impulses along the axon. It serves as an electrical insulator that prevents the dispersion of the impulses into other structures.The only type of neuron that has myelin sheath is the sensory neuron.

The process in which neurons send electrical pulses to communicate is called action potential. The neuron sends an electrical charge through depolarization and repolarization. When the axon is at resting potential, it has a negative charge inside. Depolarization is when the channels in the axon’s membrane open up and let in sodium ions, changing the charge of the axon to positive. In repolarization, potassium ions exit the the axon’s membrane which results in it having a negative charge again. The process continues all the way through the axon which carries the charge through the neuron.

The synapse has three parts to it. There is the presynaptic membrane, the postsynaptic membrane, and synaptic gap. Once the action potential has reached the axon terminal, it connects to the presynaptic membrane which then releases neurotransmitters into the synaptic gap between the nerve cells. The neurotransmitters then bind onto the postsynaptic membrane and respond in either a inhibitory or excitatory way. If it is excitatory, then the neuron receiving the action potential will continue to send it along. However, if it is inhibitory then the neuron will stop sending the action potential.