nervous system

• the nervous system

  a system to collect, process and respond to information. co-ordinates with different organs and cells in the body
• the human nervous system is divided into two categories, the peripheral nervous system and the central nervous system
• the central nervous system

  brain - centre of all consciousness, 2 hemispheres, cerebral cortex highly developed in humans

  spinal cord - extension of brain, reflex actions
• the peripheral nervous system

  autonomic - internal organs and gland control, automatic, controlled by brain stem

  somatic - controls muscles and skeletal system, regulates conscious activity, connects CNS to senses, controlled by motor cortex
• the autonomic nervous system is divided into two sections

  sympathetic - fight or flight, increases heart and breathing rate, pupils dilate, digestions and saliva stops

  parasympathetic - rest and digest, homeostatic state. decreased heart and breathing rate, pupils constrict, stimulates digestion and saliva production
• the sympathetic and parasympathetic divisions work antagonistically