Understanding the Primary Functions of the Respiratory System
The primary function of the respiratory system is to supply the blood with oxygen in order for the blood to deliver oxygen to all parts of the body. The respiratory system does this through breathing. When we breathe, we inhale oxygen and exhale carbon dioxide. This exchange of gases is the respiratory system's means of getting oxygen to the blood. The regulation of breathing is the result of a complex interaction involving a system of sensors, a respiratory control center, and an effector system to carry out its commands to the muscles and organs involved in breathing. In the respiratory system, body temperature would be the variable, nerve receptors would be the sensor, the brain would be the integrator, and muscles would be the effector. The brain stem respiratory control center regulates breathing with the help of nerves, muscles and special sensors called chemoreceptors. Chemoreceptors are specialized cells that can detect chemical substances in the body and pass that information to nerves that are part of the central nervous system for relay to the respiratory control center. In this way, breathing is constantly monitored and adjusted to maintain appropriate pH and partial pressure of oxygen in the arterial blood, that is the blood coming from the heart and that contains the highest levels of oxygen for distribution in the body. The regulation of breathing is a homeostatic control mechanism, meaning that it seeks to maintain the stability of the body's internal environment through negative feedback mechanisms. For example, high levels of carbon dioxide in the body automatically trigger quicker and deeper breathing, which in turn decreases the level of carbon dioxide by increasing the intake of oxygen. This automatic cycle can be modified or even temporarily stopped, depending on the information received by the respiratory control center from a variety of origins, such as reflexes from the lungs and airways, information from the chemoreceptors, and commands