Bio

• when you cut your finger blood oozes out.

  • You have about 5.5 litres of blood in your body!
  • Blood is a red fluid.
  • It circulates around our body in blood vessels.
  • 55% of our blood is liquid and 45% of it is the solid part made up of cells and cell fragments as illustrated in the diagram below.
  • The liquid part is called plasma.
  • The solid part is a mixture cells namely red blood cells, white blood cells and small pieces of cells called platelets.
• Red Blood Cells (RBC) are also known as Erythrocytes. They contain haemoglobin which carries oxygen from the lungs to all parts of the body. The RBC's are biconcave disc shaped with no nucleus so that they can squeeze through narrow capillaries. There are approximately 20 million per mm3 of blood