1. Circulatory System: Blood! 7SCIENCE Mon. Jan. 17

2. What is blood? Blood makes up around 8% of your body weight (5L!) Consists of: Cells and liquid Blood has many parts: Plasma Liquid part of blood, mostly water Red blood cells Has hemoglobin, important for carrying oxygen and carbon dioxide White blood cells Fight bacteria and other foreign substances Platelets Pieces of cells that help form blood clots (stop bleeding)

3. Why is it important to study? Has many functions: Carries oxygen from your lungs to the rest of the body Removes carbon dioxide from body cells and carries it to your lungs to beremoved Carries wastes from your kidneys Transports nutrients Fights infections

4. Blood Types Sometimes you may need to receive blood E.g. surgery, accident This is called a blood transfusion Must be the right type! If it is the WRONG type, the blood cells will clump together and clog the blood vessel 4 Blood Types: A,B, AB and O

5. Diseases of the blood Anemia Too few red blood cells ortoo little hemoglobin to carry oxygen Cells cannot get enough oxygen Leukemia Too many white blood cells areproduced but they cannot fight infections Treatments: Blood transfusions, bone marrow transplants, chemotherapy and radiation may be used Why is blood called the ‘tissue of life’?