Blood

  Blood is important to our body, it carries oxygen and nutrient to all parts of our bodies so that they can keep working. Human can't live without blood. Without blood, we die. There are three types of cells in our body, red blood cells, white blood cells, and platelets.

  Red blood cells are the most abundant type of cell in human body, accounting over 80% of all cells. The shape of red blood cells are normally constant, and is about 6~8 μm in diameter. Their main job is to carry oxygen from the lungs to the body tissues and carbon dioxide away from the body tissues to the lungs. They also deliver nutrients to our body tissues.

  The white blood cells are much bigger than the red blood cells, they are 5~17 μm and are white. White blood cells help fight infections and ingest matter, such as dead cells, tissue debris, and old red blood cells. They also protect you from foreign bodies that enters your blood stream.

  The smallest cell in our blood is the platelets, it is  2~4 μm in diameter. These cells' job is blood clotting. They group together and form clumps, or plugs, on a hole in the blood cell to stop the bleeding.

  Blood is very important to our body. God created blood to help us survive, He is kind and wise.

 

White Blood Cells

Red Blood Cells

Platelets