The blood

• Red blood cells in the blood

  • Becomes oxygen around body
  • Bioconcave shape - no nucleus, contains haemoglobin
• White blood cells in the blood

  • Destroys pathogens in body
  • Produce antibodies
• Platelets in the blood

  • Allows blood to clot
  • No nucleus - release chemical to clot
• Plasma in the blood

  • Carries hormones
  • Liquid that cells are suspended in
• Arteries : function, structure, adaption

  • carries blood away from the heart
  • Thick layer of elastic muscular wall + lumen
  • Think walls - can handle high pressure
  • Contracting walls help blood flow smoothly
• Capillaries : function, structure, adaption

  • exchange oxygen and carbon dioxide
  • Wall - one cell thick - narrow tube
  • Thin cell walls allow faster diffusion
  • Large surface area to volume ratio
• Veins : function, structure, adaption

  • Carries blood back to heart
  • Wide tube - thin narrow walls
  • Thin walls as blood pumped under low pressure
  • Valves to prevent back flow of blood