Fifth Grade
Worksheets
Your Blood
What is blood made of? Why do we have blood? Have you ever wondered about blood? It's pretty amazing stuff! You have blood everywhere inside your body. When you cut yourself, you make a hole in your skin. Blood leaks out through the hole. If the cut is small, it soon stops bleeding. How does this happen?
Blood is made of different kinds of blood cells. These blood cells float in a yellowish liquid. The liquid is called plasma. It is mostly water. It carries blood cells and platelets through the blood vessels. It carries dissolved nutrients from the food you eat. Your body needs these nutrients to grow. Blood also carries waste products like carbon dioxide. Waste is something your body doesn't need.
There are different kinds of things floating in the plasma. Red blood cells give the blood its red color. There are millions of them in a single drop of blood. Red blood cells are too small to see with your eyes. They can be seen with a microscope. The red blood cells carry oxygen. Oxygen is part of the air you breathe. You cannot live without oxygen. You breathe oxygen into your lungs. The red blood cells take the oxygen from your lungs. They carry oxygen to every part of your body. When the blood has a lot of oxygen, it looks bright red.
