Respiration can be divided into four major functional events Ventilation movement of air into and out of lungs Gas exchange between air in lungs and blood Tb ransport of oxygen and carbon dioxide in the ood Internal respiration: Gas exchange between the blood and tissues5 Respiration can be divided into four major functional events • Ventilation: Movement of air into and out of lungs • Gas exchange between air in lungs and blood • Transport of oxygen and carbon dioxide in the blood • Internal respiration: Gas exchange between the blood and tissues