Components of blood

• The 4 components of blood are: red blood cells, platelets, plasma and white blood cells
• White blood cells = defend against diseases
• This is a phagocyte -> white blood cell

  
• phagocyte = engulfs pathogens
• phagocytes do not have a fixed shape, can change to engulf pathogens
• White blood cells do have a nucleus
• Red blood cells don't have a nucleus --> To fit more haemoglobin --> To transport more oxygen
• Red blood cell = biconcave in shape to increase surface area for diffusion + shorten diffusion pathway
• Platelets = clot the blood (to prevent excess bleeding)
• Plasma = liquid of the blood (straw yellow), contains substances (e.g. hormones + CO2) because it absorbs. + distributes heat
• Plasma contains urea --> harmful --> urinate to get rid of
• Lymphocyte = white blood cell = produces antibodies to destroy pathogens
• Red blood cell = made of protein haemoglobin = transports oxygen