11.2 Gas Exhange Lesson

11.2 Gas Exchange in Humans - The Respiratory Systems

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Goal of the Respiratory and Circulatory Systems

• Bring O₂ to the body cells

• Take CO₂ away from the body cells

Why does the body need Oxygen?

Oxygen is used to make ATP, the cell's form of energy, in CELLULAR RESPIRATION

Step 1) RESPIRATORY SYSTEM (O₂)

1. Oxygen is moved to the lungs by inhalation

2. Oxygen moves from the lungs to the bloodstream through the heart by diffusion

Step 2) CIRCULATORY SYSTEM (O₂)

3. Red blood cells carry Oxygen in the blood to body cells in different parts of the body

Step 3) CELLULAR RESPIRATION

4. Oxygen moves from the bloodstream to the body cell by diffusion

5. Body cells use Oxygen to make ATP in the mitochondria

6. Carbon dioxide is made by the body cell as a waste product of cellular respiration

7. Carbon dioxide moves from the body cell to the bloodstream by diffusion

Step 4) CIRCULATORY SYSTEM (CO₂)

8. Carbon dioxide is carried in the bloodstream back to the heart

9. CO₂ passes from the heart to the lungs by diffusion

Step 4) RESPIRATORY SYSTEM (CO₂)

10. CO₂ leaves the lungs through the trachea to the mouth and nose in a process called exhalation