There are many organs that make up the human body. In this book, we will be learning about the lungs and the brain.

You should know that the lungs are responsible for providing oxygen and getting rid of carbon dioxide. The brain is responsible for processing information and taking in senses.

Without these we wouldn't be able to breathe or make decisions. 

The human body is organized by molecules, cells, tissue, and organs. This makes up the organ system. Collections of tissue are what make up the brain and lungs.

Have you ever thought about which buildings represent organs. In this case, the post office represents the lungs and school represents the brain. The brain is one of the most impressive organs because it is responsible for processing information which helps us make decisions, learn new things, and much more. This is why a school represents this organ.