Human Body Systems and Cell Function

• Oxygen enters the body through the mouth and nose and goes to the lungs.
• Then it goes into the circulatory system and enters the cell.
• Molecules from food and air get to the cells in the body by going through the cell membrane.
• Villi are part of the digestive system. They are tiny finger-like parts that line small intestines.
• The alveoli are part of the respiratory system. They are located at the very end of the branching tubes of the lungs. The alveoli are tiny sacs covered in blood vessels.
• The oxygen molecules can pass through the alveoli into the red blood cells.
• Even though the villi and alveoli are found in different parts of the body, they have similar functions.
• If one of the body systems stops functioning properly, it becomes more difficult for cells to get the molecules they need to function.

Test your knowledge about how oxygen and molecules from food reach the cells in the human body, and the functions of villi and alveoli in the digestive and respiratory systems. Explore how disruptions in body systems can impact cell function.