The blood

• There are four main features of blood plasma platelets red blood cells and whit blood cells
• Plasma is the liquid part of the blood and it’s Job is to transport dissolved substances around the body
• Plasma transports

  • soluble digestion products (glucose ) from the small intestine to other organs.
  • carbon dioxide from the organs to the lungs to be breathed out.
  • the waste product urea from the liver to the kidneys to be excreted in urine
• Red blood cells transport oxygen from the lungs to the body cells
• Red blood cells contain haemoglobin which is a protein that binds to oxygen
• Red blood cells have no nucleus which means they have more room for haemoglobin
• Red blood cells have a biconcaved disk giving the cell a greater surface area so that oxygen diffuses in and out rapidly
• White blood cells form a part of the immune system for example making anti bodies
• White blood cells contain a nucleus which contains dna which encodes the instructions that they need to do their job
• Platelets are tiny fragments of cells and their job is to help blood clot
• Donated blood purposes

  • used to replace blood lost durning injury
  • some people are given platelets extracted from blood to help clotting
  • protiens extracted from blood can be useful for antibodies
• In a blood transfusion we have to make sure the donated blood is the same type as the patients otherwise the body’s immune system will reject the blood and the patient could die
• Lots of diseases can be transmitted in blood in the uk blood is screend for infection so the Risk is low