blood cells

• red blood cells carry oxygen from the lungs to all cells in the body
• there shape is a biconcave disc - gives large SA for absorbing oxygen . they also dont have a nucleus allowing for more room to carry oxygen
• more red blood cells = more oxygen that can get to cells in the body
• white blood cells defend against infection by engulfing bacteria and releasing toxins which is called phagocytosis
• other white blood cells produce antibodies to fight microorganisms, as well as antitoxins to neutralise toxins. unlike red blood cells they do have a nucleus
• platelets help the blood clot, they are small fragments of cells that are released from the bone marrow
• platelets help the blood to clot at wounds to stop exessive blood loss and microorganisms entering the body
• plasma in the blood carries just about everything in the blood, such as red and white blood cells, platelets, glucose amino acids and urea