Answer:
Describe the passage of air from the outside environment to the lungs
Explain how the lungs are protected from particulate matter
Describe the function of the circulatory system
Describe the cardiac cycle
Explain how blood flows through the body
Animals are complex multicellular organisms that require a mechanism for transporting nutrients throughout their bodies and removing wastes. The human circulatory system has a complex network of blood vessels that reach all parts of the body. This extensive network supplies the cells, tissues, and organs with oxygen and nutrients, and removes carbon dioxide and waste compounds.
