Neurotransmitters, Endocrine System, Drugs

Nervous System = electrochemical communication network including all nerve cells

Central Nervous System = brain and spinal cord — more than 99% of nerves are in CNS

Peripheral Nervous System = network of nerves connecting the brain and spinal cord to other body parts

• Nerves = electrical cables from bundles of axons

• Somatic Nervous System = division of peripheral nervous system that controls voluntary movement of skeletal muscles

• Autonomic Nervous System = division of PNS controlling glands & internal muscle organs

  • sympathetic nervous system = arouses body to mobilize in stressful situations

  • parasympathetic nervous system = calms the body and conserves energy after stress