The air ways, the lungs, and the blood vessels that picks up fresh oxygenated air and send it through to every cell in the body is what life is all about. To trace a bit of air from its entrance into the nostrils—the openings of the nose that continue on toward the lungs—first there must be a breath, or a breathing in. Secondly, breathing out of the exhaust, or carbon dioxide to rid the body of toxic accumulations, completes the cycle.
The respiratory system is life itself. Without the lungs and the airways supplying oxygen, a human being would be nothing more than inert matter. Yet, carrying fresh oxygen to the body is only half of the function of this important life giving system; the other half is disposing of carbon dioxide, the residual effect of oxidation. What organs, systems or conduits make up this breathing system?
This process takes far more time than a mere breath or an exhale, but the continuous act of breathing in and breathing out must be ongoing. It can be either automatic—without a person even thinking about it— or it can be controlled by the individual. Usually deep breathing is controlled since taking a deep breath and holding the breath for a few seconds is necessary in some diagnostic tests, as in chest x-rays, as an example. Deep breathing takes in more oxygen at one time than does normal breathing and this speeds the overall activity of the system. Breathing through the nose is preferable to breathing through the mouth, although breathing out is often done through the mouth, especially if a deep controlled breath of air has been taken in.
After the air has initially been taken in it moves on through the passageways to the voice box, or trachea, and then to the bronchial tube and its branches. This tree-like form of the lobes of the lungs, in actual function as well as in appearance—trees utilize the carbon dioxide that humans and animals breathe out and turn it into oxygen— circulates fresh air for stale air through an intricate drop off and pick up system that takes place in the lungs in the minute bronchioles and their ending bundles, or alveoli.
Carbon dioxide is removed from the body via the pulmonary artery, and the veins pick up the oxygenated blood and carry it to the heart where it is pumped out through the arteries to all parts of the body. (Note that the pulmonary blood flow system is opposite from the heart generated system where the arteries carry fresh blood and the veins carry carbon dioxide.
The lungs are the most important part of the respiratory system; although without the support of the passageways and the muscles, the lungs would cease to function properly. The lungs are somehow in a rough shape of a butterfly, in that the sternum is in the mid section and the five lobes are on the right and left of the mid chest bone.
The diaphragm, a “dome-shaped muscle located below the lungs” is necessary for breathing. Without the powerful thrust of this muscle, the air would not circulate. In addition to this muscle, all the surrounding muscles in the rib cage, the abdominal muscles and muscles of the neck and vicinity all contribute to making this a vital part of the respiratory system.
Viewed totally, as an integral part of the whole body, blood, immune system, brain, and bones, this system is only one of many. Viewed separately, it looms large and tends to lean toward being the most important system of the whole living body.