Blood

• Blood is a tissue consisting of plasma, in which the red blood cells, white blood cells and platelets are suspended
• Red blood cells: carry oxygen around the body
• Red blood cells

  • Contain haemoglobin, a protein that binds oxygen
  • they don’t have a nucleus so more haemoglobin can fit in
  • their biconcave shape gives a large surface area for oxygen absorption and flexibility for fitting in tiny capillaries
• White blood cells: help to protect the body against infection
• Platelets: prevent bleeding by helping blood to clot
• Plasma: a liquid that carries everything found in blood
• things carried by plasma in blood

  • Red blood cells
  • White blood cells
  • Platelets
  • carbon dioxide
  • proteins
  • hormones
  • urea
  • dissolved nutrients (E.g. glucose and amino acids)