Transport Animals

• How is the plant transport system different to mammals?

  • Animals require more energy
  • Have more advanced needs (locomotion, nervous system, large brains)
  • Larger in size (surface area : volume ratio)
• Circulatory System


  • Made up of a pump (the heart) which keeps blood flowing through blood vessels (system of interconnecting tubes)
  • Blood is the liquid that carries materials
  • Valves ensure blood flows in only one direction

  
• Single Circulatory System


  • Found in fish
  • Blood passes through the heart only once on a complete circuit
• Double Circulatory System


  • Found in mammals (also birds and reptiles)
  • The blood passes through the heart twice on one complete circuit of the body
  • Pulmonary and Systemic circuits

  
• Advantages of double circulatory system over a single one


  • More efficient in delivering oxygen to cells
  • Double circulation maintains higher blood pressure, so blood can travel faster
  • Greater flow of blood to tissues
• Blood


  • Plasma
  • Red blood cells
  • White blood cells
  • Platelets

  
• Plasma


  • Transports carbon dioxide, digested food, urea, hormones and heat energy
• Red blood cells


  • Adapted for oxygen transport: shape, absence of nucleus, presence of haemoglobin

  
• Red blood cells


  Transport oxygen
• Red blood cells


  Contain the red pigment haemoglobin, a globular protein that binds oxygen
• Haemoglobin


  Contains iron
• Red blood cells


  • Small (approx. 7μm)
  • Allows substances to diffuse quickly in/out
  • Can squeeze into very small capillaries to bring blood close to cells
  • Biconcave disc
  • Increases the surface area to allow substances to diffuse quickly in/out
  • Flexible
  • Can squeeze into very small capillaries to bring blood close to cells
  • No nucleus
  • More space for haemoglobin molecules – which maximising the amount of oxygen carried by each cell

  
• White blood cells


  Involved in immunity (fighting disease)
• White blood cells


  • Different types with different functions
  • Two main groups: phagocytes and lymphocytes

  
• Phagocytes


  • Involved in immunity
  • Engulf and destroy microorganisms by phagocytosis
  • Lobed nuclei and granular cytoplasm

  
• Lymphocytes


  • Involved in immunity
  • Produce antibodies
  • Smaller than most phagocytes
  • Have large, round nucleus and less cytoplasm
• All of the blood cells are made in the bone marrow
• Platelets


  • Small fragments of cells with no nucleus
  • Involved in blood clotting
  • Blood clotting prevents bleeding (blood loss) and stops pathogens entering the body through breaks in the skin
• Plasma


  • The liquid part of blood
  • Water, containing many dissolved substances
  • Plasma proteins (fibrinogen and antibodies)
  • Lipids (cholesterol and fatty acids)
  • Glucose
  • Urea (excretory substance)
  • Mineral ions (Na+ and Cl-)
  • Hormones
  • Dissolved gases (CO2)
• What does blood transport?


  • Oxygen
  • Carbon dioxide
  • Nutrients (glucose, amino acids, water, vitamins, minerals)
  • Urea (waste product)
  • Hormones
  • Plasma proteins (including fibrinogen and antibodies)
• Deoxygenated blood enters the right atrium through the superior vena cava or inferior vena cava.