1. Functions of the Respiratory System Brings oxygen in from the environment for our body cells, and removes carbon dioxide waste. Main components: – Nose – Pharynx: part of the throat behind nasal cavity and mouth. – Larynx: voice box, houses vocal cords. – Trachea: windpipe, air travels from trachea toward the lungs.

2. Respiratory System Components continued: – Bronchi: or bronchus (singular). The bronchi bring air into the lungs. – Bronchioles: bronchi branch into smaller airways that carry air to the alveoli. – Alveolus: or Alveoli (plural). Structures in the lungs where gas exchange occurs. Oxygen leaves the alveoli and goes into the bloodstream to be taken to our cells. Carbon dioxide leaves the blood and into the alveoli to be breathed out.

3. Pharynx Nose Larynx Bronchioles Bronchus Trachea Alveolus LEFT LUNG RIGHT LUNG

5. The Lungs The lungs: expand and contract to bring air in and force air out of the body. When we bring air into the body it is called inhalation. When we force air out (breathe out) it is called exhalation. The process of breathing in and out is controlled by a muscle called the diaphragm.

6. Diaphragm LEFT LUNG RIGHT LUNG

7. Breathing The process of breathing is known as respiration. When the diaphragm contracts and pulls downward the lungs expand and pull air in. When the diaphragm relaxes it pushes upward and the lungs contract and push air out.

8. Disorders of the Respiratory System Lung damage can occur due because of breathing in chemicals (like pollutants, cigarette smoke, asbestos, and fumes). Emphysema: lung tissue damage, that causes problems breathing. – Most cases of emphysema develop in smokers, or those exposed to second hand smoke. – Tar buildup in the lungs causes lung tissue damage.

10. Review Air moves through the respiratory system: – Nose – Pharynx – Larynx – Trachea – Bronchi – Lungs – Bronchioles – Alveoli Breathing in: Inhalation Breathing out: Exhalation Review Video