Heart and lung anatomy. Artwork of an oblique anterior (left-frontal) view of the heart and lungs in a male body. One lung is shown at right. The heart (centre) is a hollow muscle that pumps blood around the body and to the lungs. Some of the major heart blood vessels are also shown. Air passes into and out of the lungs through the trachea (vertical), with the pharynx and nasal passages at top. In the lungs, the process of gas exchange with the blood adds oxygen and removes carbon dioxide.