The respiratory system’s main function is gas exchange, mainly carbon dioxide to oxygen via osmosis. It also enables speech and sound, and has an extensive defense system against pathogens.

Parts & Functions Involved in Respiring (Breath)

The first five parts listed below make up the conducting zone, and the last four make up the respiratory zone.

• Larynx – houses the vocal chords
• Trachea – air tube connecting to the bronchi
• Bronchi – left and right tubes that carry air to and from the lungs respectively
• Bronchioles – non-cartilaginous branches of the bronchi, distribute air to alveoli
• Terminal bronchioles – branches of the bronchioles
• Respiratory bronchioles – branches of terminal bronchioles, with sporadic alveoli
• Alveolar ducts – each lung holds 1.5-2 million of them, and they are responsible for 10% of gas exchange
• Alveoli – responsible for 90% of gas exchange, sacs found sporadically on the respiratory bronchioles the alveolar ducts, within the alveolar sacs and at the end of each branch
• Diaphragm – shelf of muscle separating the thoracic cavity from the abdominal cavity (critical to making room for aspiration)

Respiratory Fun Facts

Lined up end to end, the lungs’ airways would be about 1,490 miles (2,400 km) long. The average person take 21,600 breaths per day. 70% of the body’s waste products leave through breath. The brain uses 25% of the body’s oxygen and is only 2-3% of its mass.