Respiration - the act of breathing;

Respiration - the act of breathing; it includes the intake of oxygen and the output of carbon dioxide.
 External respiration – refers to the interchange of oxygen and carbon dioxide between the alveoli of the lungs and the pulmonary blood.  Internal respiration –takes place throughout the body; the interchange of same gases between the circulating blood and the cells of the body tissues.  Inhalation/Inspiration – refers to the intake of air into the lungs.  Exhalation/Expiration – refers to the breathing out or the movement of gases from the lungs to the atmosphere.  Ventilation – another word that is used to refer to the movement of air in and out of the lungs.