The respiratory system controls breathing processes in the body. Two lesser known processes involve the respiratory system and homeostasis. Parts of the respiratory system can help stabilize pH levels in the blood and regulate the body's temperature. In addition, the gas exchange processes and actual breathing mechanisms facilitated by the respiratory system may be considered a form of homeostasis.
Homeostasis may be thought of as the internal thermostat for a living organism. It represents mechanisms that help keep the organism’s body systems in a stable, comfortable, and functional state. Some of the factors that homeostasis is responsible for within a human being include body temperature, blood sugar levels, and acidity levels.
All homeostatic processes rely on sensory, control, and motor components. The sensory component, called a receptor, catalogs environmental changes or stimulation and sends this information to a command center, usually the brain. This control mechanism in turn relays instructions for responding to the change towards organs, muscles, or other components that perform actions. The related action may take the form of either increasing or decreasing the production of some substance or initiating some other process. These homeostatic actions are known as positive feedback and negative feedback, respectively.
Negative feedback helps facilitate breathing, so it fuels the processes of homeostasis and the respiratory system. The rib cage and a muscle called the diaphragm both may change the size and volume of the main breathing organs, the lungs. Through breathing stimulation, these components either lower or rise up. When the rib cage rises, the lungs expand, which decreases air pressure. This pressure is then restored or balanced out upon inhaling air into the lungs.
Another direct link exists between the respiratory system and homeostasis, as the former must keep itself in the latter state. The whole gas exchange process between carbon dioxide and oxygen that sustains the respiratory system is an example of homeostasis. The lungs, trachea, and other components help the body get rid of wasteful carbon dioxide. At the same time, the body is gaining needed oxygen for vital processes through the respiratory system.
The process of carrying carbon dioxide into the respiratory system for exhalation aids with another connection between the respiratory system and homeostasis: blood pH balance. The respiratory system performs conversions on carbon dioxide particles brought to it via blood. These conversions lessen hydrogen particles. As a result, the acid and base, or pH, spectrum of the blood reaches more of a middle state. Abnormal pH levels can create a number of adverse and even fatal health consequences, so control of this homeostasis mechanism is vital.
This effect allows more efficient oxygen intake into the blood. Therefore, not only does the respiratory system help maintain homeostatic pH functions, but the resulting homeostasis helps the respiratory system work more efficiently. In a similar manner, pH can impact where and when blood deposits oxygen for respiration on the cellular level.
Cellular respiration consists of the chemical processes that provide cells energy. These cellular metabolic reactions are largely responsible for creating body heat. Therefore, the respiratory system also plays a role in body temperature homeostasis.
The merging of the respiratory system and homeostasis in body temperature control is particularly pronounced in organisms like reptiles. For these animals, body temperature rises and falls in response to the outside environment. In such cases, the organisms might breathe more slowly in hot environments to conserve energy and better regulate body temperature.
