The process of that takes oxygen into the body and releases carbon dioxide.

The process of taking air into the lungs (inhalation) and the process of breathing it out (exhalation).

A system of chambers through which air passes from the nostrils to the pharynx.

Windpipe; series of cartilaginous rings through which inhaled air moves from the larynx to the bronchi.

Hair-like projections that contract to keep foreign particles out of passageways.

Area of the throat between the mouth and the vocal cords.

A cartilaginous structure on top of the trachea containing vocal cords; the voice box.

Sac-like organs in the chest that allow the exchange of oxygen and carbon dioxide with red blood cells.

Either of two main branches of the trachea which lead to the lungs.

Smaller branches of the bronchi in the lungs that end at the alveoli.

Tiny air sacs in the lungs that are the site of gas exchange with capillaries.

A sheet of muscle extending across the bottom of the rib cage that functions in respiration.