1. Respiratory System

2. Respiration – Breathing – intake of oxygen and expel of carbon dioxide – Cellular respiration – cell making ATP – Exchange of gases between atmosphere, blood, and cells

3. Components Nose/mouth – take in air Pharynx – windpipe – passageway for air Larynx – voice box Trachea – passageway for air Bronchi – branching of trachea into 2 lungs Bronchioles – smaller branches of bronchii Alveoli – sac at the end of bronchioles, where gas exchange occurs

4. Components

5. Breathing Involves the diaphragm Muscle that separates thoracic cavity from abdominal cavity When diaphragm contracts, it drops and air is taken in When diaphragm relaxes, it rises and air is pushed out

6. Pathway of Air In through nose/mouth – filled with oxygen Down pharynx, through trachea/larynx Into bronchi, through bronchioles, into alveoli Oxygen diffuses into capillaries, carbon dioxide diffuses into alveoli Carbon dioxide travels back through passageways out of body