Human Nervous System

Human nervous system:

A) Central nervous system (CNS)– consists of the brain and the spinal cord

B) Peripheral nervous system (PNS) – composed of nerves which connect the CNS to the other parts of the body.

1. Somatic system (skeletal) – nerves (motor and sensory) that control the muscular system and the external sensory receptors
2. Autonomic system - autonomic motor neurons that control the internal organs (such as heart, arteries, gastrointestinal tract, glands..)
3. Sympathetic system - responds to stressful stimulation – prepares the body for fight or flight response

   Parasympathetic system – involved in relaxation and has an energy conserving function