Functions of the Respiratory System

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. Nose Pharynx Larynx Trachea Bronchus Bronchioles LEFTLUNG RIGHTLUNG Alveolus

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. LEFTLUNG RIGHTLUNG Diaphragm

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