Trauma Survivors Network - provided by ATS

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A Program of the ATS

Respiratory System

The pulmonary system is designed to carry oxygen to the blood. It is composed of the lungs and all the tubes or airways leading to the lungs. The upper respiratory tract is composed of the nose, whose function is to warm, moisten, and filter air. Next are the naso and oropharynx areas that travel down behind the mouth and feed into smaller bronchi. At the level of the bronchi begins the lower respiratory tract, which is made up of the bronchi, smaller bronchioles and eventually alveoli. It is at the level of the alveoli that oxygen exchange occurs in the lung. The lungs are inflated by the muscles of respiration, namely the diaphragm and deflated by the abdominal muscles.


The Respiratory System - Glossary

Bronchi: The two main air passages into the lungs.

Diaphragm: The main muscle used for breathing; separates the chest cavity from the abdominal cavity.

Epiglottis: A flap of cartilage that prevents food from entering the trachea (or windpipe).

Esophagus: The tube through which food passes from the mouth down into the stomach.

Heart: The muscular organ that pumps blood throughout the body.

Intercostal muscles: Thin sheets of muscle between each rib that expand (when air is inhaled) and contract (when air is exhaled).

Larynx: Voice box.

Lungs: The two organs that extract oxygen from inhaled air and expel carbon dioxide in exhaled air.

Muscles attached to the diaphragm: These muscles help move the diaphragm up and down for breathing.

Nasal cavity: Interior area of the nose; lined with a sticky mucous membrane and contains tiny, surface hairs called cilia.

Nose hairs: Located at the entrance of the nose, these hairs trap large particles that are inhaled.

Paranasal sinuses: Air spaces within the skull.

Pharynx: The throat.

Pleural membrane: Covering the lung and lining the chest cavity, this membrane has 2 thin layers.

Pulmonary vessels: Pulmonary arteries carry deoxygenated blood from the heart and lungs; pulmonary veins carry oxygenated blood back to the heart.

Respiratory center: Area of the brain that controls breathing.

Ribs: Bones attached to the spine and central portion of the breastbone, which support the chest wall and protect the heart, lungs, and other organs in the chest.

Trachea: Tube through which air passes from the nose to the lungs (also known as the windpipe).

Illustration Provided by: Leslie Laurien, M.S.M.I.