Your respiratory system provides the energy needed by cells of the body. Air is breathed in through the nasal cavity and/or mouth and down through the throat (the pharynx). The throat has three parts - the nasopharynx, the oropharynx, and the laryngopharynx. The air passes down the trachea (the windpipe), through the left and right bronchi, and into the lungs. Oxygen in the blood is delivered to body cells, where the oxygen and glucose in the cells undergo a series of reactions to provide energy to cells, and the waste product of this process is carried out of the lungs.
The larynx is your voice box; the epiglottis, a flap of cartilage that prevents food from entering the trachea; and the esophagus, the tube through which food passes to the stomach.
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).
