Paralysis is loss of muscle function for one or more muscles. Paralysis can be accompanied by a loss of feeling (Sensory loss) in the affected area, if there is sensory damage as well as motor. The chain of nerve cells that runs from the brain through the spinal cord out to the muscle is called motor pathway. Normal muscle function requires intact connections all along this pathway. Damage at any point reduces the brain's ability to control the muscle's movements. This reduced efficiency, causes weakness, also called paresis. Complete loss of communication prevents any willed movement at all. This lack of control is called paralysis.