Communication Systems

External Environment
1. Can be air, water or soil. It can change and put the organism under stress
  1. Slow changes e.g. Season change/global warming
  2. Fast change e.g. Day to night/sunshine to darkness
Detecting changes
1. High blood sugar levels after a meal
  1. Body releases insulin - hormonal
2. Smelling delicious food
  1. Mouth waters - nervous
3. Torch shone in eye
  1. Pupils contract - nervous
4. Sudden drop in external temperature
  1. Shiver - nervous
Internal Environment
1. Cells...
  1. ...do metabolic reactions, use up substrates and produce products e.g. CO2
    1. CO2 needs excreting
      1. This means the removal of waste to prevent accumulation in the blood
        CO2 needs excreting as it can build up in tissue fluid ad disrupt enzyme action of cells, and change pH levels
  2. ...are bathed in tissue fluid which is made from the blood

Resumen del Recurso

	Creado por beccadavies19 hace casi 10 años