Physiology, Respiratory Drive

Excerpt

Breathing is a complex process that relies heavily on the coordinated action of the muscles of respiration and the control center in the brain. The primary function of the lungs is to facilitate gas exchange between inspired air and the circulatory system. It helps bring oxygen to the blood and remove carbon dioxide from the body. Oxygen is critical for proper metabolism on a cellular level, while carbon dioxide is crucial for achieving adequate PH levels. Several mechanisms exist to ensure a rigorous balance between supply and demand. In response to a change in blood gases, the pulmonary system adapts by adjusting breathing patterns to help meet the body's metabolic demand.

Exercise, for instance, increases oxygen consumption and raises carbon dioxide production. Should, at any point, the available oxygen supply fails to meet the necessary demand, aerobic metabolism ceases, and energy production declines. Likewise, if carbon dioxide accumulates without proper disposal, the blood becomes more acidic, and cellular damage ensues, ultimately leading to organ failure. Neither outcome is desirable; therefore, numerous mechanisms exist to match respiration with the continually changing demands. Central and peripheral chemoreceptors, as well as mechanoreceptors in the lungs, convey neural and sensory input to the brain to help modulate respiratory drive. The respiratory center responds in return by changing its firing pattern to alter breathing rhythm and volume.