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Respiratory system

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Respiratory system

Respiratory system, showing sinuses, pharynx, larynx, trachea, bronchial tubes, and lungs, with detail of bronchiole and alveoli.

The upper respiratory tract (upper airway) consists of the nose, mouth, sinuses, pharynx (upper section of the throat), and larynx (voice box). The lower respiratory tract consists of the trachea (windpipe), bronchial tubes, and lungs. The bronchial tubes carry air into the lungs and branch into smaller and smaller bronchioles. These end in alveoli (air sacs).

The main function of the respiratory system is to supply the blood with oxygen so the blood can deliver oxygen to all parts of the body. The respiratory system does this through breathing.

Current as of: October 26, 2020

Author: Healthwise Staff
Medical Review:
E. Gregory Thompson MD - Internal Medicine
Adam Husney MD - Family Medicine
Robert L. Cowie MB, FCP(SA), MD, MSc, MFOM - Pulmonology
Lesley Ryan MD - Family Medicine

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This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. Learn how we develop our content.