Chapter 1 PARTS WORKING TOGETHER Each part of the body has a job The parts work together Parts that work together are called a system The body has many systems One system helps the body turn food into energy Another system helps the body breathe Another helps the body to move The parts of your body work together What are parts that work together called 4
The Circulatory System One important body system is called the circulatory system This system’s job is to pump blood to all parts of the body The circulatory system is made up of the heart the blood and many strong tubes called blood vessels The heart makes the blood move through the blood vessels Blood vessels carry the blood to all parts of the body Blood vessels are tubes that carry blood to all parts of the body 5
Cells All body parts are made of cells Cells are so small you need a microscope to see them The human body has many different kinds of cells It has muscle cells and bone cells It has skin cells and brain cells It has nerve cells and blood cells Your body is made of millions of tiny cells A photographer used a microscope to take this picture of cells from inside a bone 6
Every cell needs food to live Food goes into the blood each time we eat or drink Every cell also needs oxygen Oxygen is a gas in the air Oxygen goes into the blood every time we take a breath The blood carries food and oxygen to every cell Your body breaks down everything you eat or drink Then your blood carries the food to your cells 7
