Neurons are the basic structural and functioning units of the nervous system. The finger-like nerve processes extending from the nerve cell body are consisting of axons and dendrites which conduct and transmit impulses. These axons and dendrites are bundled into nerves.
Axons carry the impulses away from the cell body conveying it to various regions. Dendrites carry impulses toward the cell body. Dendrites are shorter and more numerous than axons.
Neurons are categorized as either sensory, motor or interneurons.
Sensory neurons send impulses from external stimuli and internal organs to the central nervous system.
Motor neurons transport impulses from the central nervous system to glands, organs and muscles.
Interneurons link impulses between the sensory and motor neurons.
Depending on their role and function, some neurons have many branches or few dendritic branches and have short axons or long axons. The longest axon is about 3 feet that stretches from the bottom of the spine to the big toe.
In transmitting impulses between neurons, they utilize both electrical and chemical messengers. As the dendrites of neurons received the impulses, they are passed down to the cell body and onto the axon. Then continue to travel down the length of the axon as action potential, a form of electrical signal.