the nervous system

• what is the nervous system?

  a specialised network of cells in the body and is our primary internal communication system
• what are the 2 main functions of the nervous system?

  - to collect, process and respond to info in the environment

  - to co-ordinate the workings of diff organs and cells in the body
• what are the divisions of the nervous system?

  
• what is the CNS made up of?

  brain and spinal cord
• what are the 2 functions of the CNS?

  the control and regulation of the bodys physiological processes
• what does the brain do?

  receives and processes sensory information from srs so provides conscious awareness to send msgs to muscles and glands
• what does the spinal cord do?

  relays messages from CNS to rest of body, to and from brain and connects nerves to PNS
• whatv does the PNS do?

  transmits msgs via millions of neurons to and from nervous system
• what are the 2 divisions of the PNS?

  somatic and autonomic
• what does the ANS do?

  coverns vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses

  involuntary actions
• what does the SNS do?

  controls muscle movement and receives information from sensory receptors

  transmits info from receptor cells in sense organs to CNS

  receives info from CNS that directs muscles to act

  involved in reflex actions with CNS so reflex happens quickly

  controls voluntary movement e.g moving your hand
• what is the ANS split up into?

  sympathetic and parasympathetic
• what does the sympathetic branch do?

  prepares body for fight or flight using neurotransmitter noradrenaline results in increased heart rate, increased breathing, dilated pupils, inhibits digestion
• what does the parasympathetic branch do?

  activates rest or digest e.g constricting pupils, lowerng heart-rate, stimulates digestion, salivation