Most technological systems are primitive compared to the human body's ability to precisely regulate numerous critical variables and intricate biological processes. This remarkable capacity to maintain a consistent internal environment is referred to as homeostasis. The respiratory system -- which comprises the nose, the mouth, the lungs and several other organs involved in breathing -- is involved in various important aspects of homeostasis.
Oxygen In, Carbon Dioxide Out
The respiratory system participates in a variety of homeostatic processes, and the two most important of these are maintaining pH and regulating gas exchange. Both of these homeostatic functions are related to the biochemical roles played by the two primary respiratory gases, carbon dioxide and oxygen. Oxygen enters the body as a component of the air we breathe and is processed by the lungs. Carbon dioxide, which is produced as a byproduct of cellular metabolism, travels through the bloodstream to the lungs and is exhaled.
Carbon dioxide and oxygen
The activity of the human body is a manifestation of the combined labors of trillions of microscopic cells. The body needs food to eat and air to breathe, and the requirements of individual cells are similar. The fundamental reaction that enables cellular life transforms glucose and oxygen into carbon dioxide, water and energy. This is why the supply of oxygen in the bloodstream is a critical aspect of homeostasis -- with insufficient oxygen, cells cannot make energy. Carbon dioxide must also be carefully managed so that this waste product does not accumulate to problematic levels. By inhaling and exhaling, the respiratory system is able to take in oxygen and release carbon dioxide, and thus it plays a dominant role in homeostatic gas exchange.
The Proper pH
The acidity or alkalinity of a substance is measured by the pH scale, which typically ranges from 0 to 14. Many biological structures and processes are designed to operate within a narrow pH range. Proteins, for example, experience detrimental structural changes when exposed to an environment with improper pH. The pH of any substance depends on its concentration of hydrogen ions. The concentration of hydrogen ions in blood depends on the concentration of carbon dioxide, which is directly influenced by the respiratory system. Thus, the respiratory system plays a major role in maintaining the human bloodstream at the optimal pH.
Additional Respiratory Roles
The respiratory system participates in several other processes related to the body's ability to remain consistently healthy and functional despite internal and external stresses. Exhaled breath, which is warm and contains moisture, is a means of regulating the body's water content and internal temperature, and the movement of the lungs contributes to optimal blood circulation. The respiratory tract influences the composition of blood passing through the lungs, and it protects the body from the numerous microbes and contaminants that are inhaled along with air.
- University of Southern California: Homeostasis
- Ohio State University: Anatomy of Respiratory System
- West Virginia University: The Respiratory System
- HyperPhysics: Examples of pH Values
- University of Southern California: The Renal-Respiratory System
- University of Southern California: Bicarbonate
- Elmhurst College: Oxygen Transport
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