The Nervous System Its super fast and rocks my socks literally, it can! 2 major divisions 1.Central NS: brain and spinal cord ~ command center of the body 2.Peripheral NS: anything not brain or s.c. ~ has 2 major division 1.Somatic division ~ 2 divisions 1.Sensory- afferent- input 2.Motor- efferent- output 2.Autonomic division ~ has 2 major divisions 1.Sympathetic- excited reactions- inhibits digestion 2.Parasympathetic- calming reactions- enhance digestion Organization of the NS Organization of the NS (for my super-visual friends) Sensory (afferent) input Motor (efferent) output Autonomic Division of PNS Somatic Division of PNS External stimuli sensed (eyes, ears, etc) sensory neuron interneuron motor neuron