1. The Nervous System

• 1. Nervous System

  • Network of cells in body; primary internal communication system.

  Main functions:

  • collect/respond to environmental info.
  • co-ordinate organs/cells.
• 2. Nervous System - CNS

  Central Nervous System (CNS):

  • brain/spinal cord - commands/decisions.
• 2a. Nervous System - CNS

  Spinal Cord - sends messages to/from brain.

  • connects nerves to PNS.
  • co-ordinates bodily processes.
  • reflex actions.
  • works in pairs to connect to specific glands/muscles.
• 2b. Nervous System - CNS

  Brain - conscious awareness.
• 2c. Nervous System - CNS

  Brain - Cerebrum:

  • 2x on brain sides.
  • Frontal lobes (speech/thoughts).
  • Temporal lobes (hearing/memory).
  • Parietal lobes (sensory info).
  • Occipital lobes (visual info).
• 2d. Nervous System - CNS

  Brain - Cerebellum:

  • motor skills.
  • balance.
  • muscle co-ordination.
• 2e. Nervous System - CNS

  Brain - Diencephalon:

  • thalamus - relay station for nerve impulses from senses.
  • hypothalamus - regulates bodily function (e.g. hunger); controls release hormones; links endocrine/NS.
• 2f. Nervous System - CNS

  Brain - Brain Stem:

  • automatic functions.
  • motor/sensory neurones connect impulses between brain/spinal cord.
• 3. Nervous System - PNS

  Peripheral Nervous System (PNS):

  • messages to/from CNS.
• 3a. Nervous System - PNS

  Somatic Nervous System (SNS) - info from receptor cells to CNS.

  • sensory neurones - relay msgs to CNS.
  • motor neurones - relay msgs from CNS.
  • fast reflex actions (controls muscle movement).
• 3b. Nervous System - PNS

  Autonomic Nervous System (ANS) - regulates involuntary/automatic actions (e.g. heartbeat).

  • sympathetic + parasympathetic NS.
• 3c. Nervous System - PNS


  Sympathetic Nervous System:

  • emergency response (fight/flight).
  • neurones from SNS travel to organs, prepare body for action.
  • releases stored energy, slows unimportant bodily functions (e.g. digestion).
• 3d. Nervous System - PNS

  Parasympathetic Nervous System:

  • relaxes body after response of sympathetic n.s.
  • slows heartbeat, reduces blood pressure, restarts digestion.
  • rest + digest.
• 4. Nervous System

  Nervous System

  CNS - spinal cord/brain.

  PNS - SNS + ANS (sympathetic/parasympathetic).