Further Biology - Blood

CAPILLARIES deliver food and oxygen to each cell

• Capillaries use diffusion to deliver food and oxygen directly to body tissues and take carbon dioxide and other waste materials away
• Walls only one cell thick to make it easy for substances to pass in and out of them
• They have a very small hole down the middle
• They are too small to see without a microscope

BLOOD is made up of  FOUR PARTS:

• WHITE BLOOD CELLS
• RED BLOOD CELLS
• PLASMA
• PLATELETS (small fragments of cells that help blood to…