Neuron - are electrically excitable cells in the nervous system that process and transmit information.
The brain or encephalon - is the control center of the central nervous system.
The spinal cord - is a thin, tubular bundle of nerves that is an extension of the central nervous system from the brain, enclosed and protected by the bony vertebral column. 
A reflex - action is an automatic (involuntary) neuromuscular action elicited by a defined stimulus.
Nervous tissue - is composed of neurons, which transmit impulses, and the neuroglia, which assist propagation of the nerve impulse as well as provide nutrients to the neuron.
Cerebrum - The telencephalon is the name for the forebrain, a large region within the brain to which many functions are attributed, which many people refer to as the cerebrum.
The peripheral nervous system - resides or extends outside the central nervous system serving the limbs and organs.
The somatic nervous system - is the part of the peripheral nervous system associated with the voluntary control of body movements and with reception of external stimuli.
Motor neurons - begin in the central nervous system projecting their axons outside the CNS and directly or indirectly controlling muscles.
Dendrites - are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body of the neuron.