The lower respiratory tract is the part of the respiratory system that carries air from the lower airway into the lungs and includes the trachea, bronchi, bronchioles, and lungs.
The lower respiratory tract conducts air toward the areas where gas exchange occurs. Within the lungs, the smallest airways lead toward the alveoli, where oxygen enters the blood and carbon dioxide leaves it.
Infections affecting these structures can be more serious than many infections limited to the upper respiratory tract, although severity varies considerably.
SEE ALSO
- Lower Respiratory Tract Infection
- Upper Respiratory Tract
- Bronchitis
- Pneumonia