Communication and homeostasis

• Multicellular animals and plants

  • Complex, many organs/tissues with specific functions
  • Vital cells, tissues and organs’ activity are coordinated
  • Done by nervous and endocrine systems
  • Detect external/internal environment change
  • Effector does response
  • Animals
  • Control activity in bodies
  • Responding to stimuli increases survival
  • Avoiding harmful conditions
  • Maintain metabolism optimum conditions
  • Plants
  • No nervous system
  • Cells produce chemicals with hormone type effects; plant growth regulators
  • Coordination relies on cell signalling (cell-cell communication)
• Definitions

  • Internal Environment: Conditions inside body
  • External Environment: Conditions outside body
  • Stimulus: Environmental change, causing response
  • Response: Change in behaviour or physiology
  • Effector: Body part causing response (e.g. muscle or gland)
• Efficient animal communication system

  • Cover whole organism
  • Allow for cell signalling
  • Specific and rapid communication
  • Result in short and long term responses