Function of the Respiratory System
The primary function of the respiratory system is to provide the required oxygen and remove carbon dioxide from the body. By the removal of carbon dioxide, this system helps maintain the pH of the blood at 7.4. An-other important respiratory system function is to help with the production of sound (e.g., speaking, singing).
The upper part of the respiratory system houses the sensory receptors for smell, which are stimulated by chemicals present in the air the body breaths. The respiratory system helps eliminate some water andheat as air is breathed in and out. The movement ofthe respiratory muscles and the resultant changes in volume and pressure inside the thoracic cavity helpincrease venous return and lymphatic drainage. In ad-dition to these functions, certain cells in the respira-tory system help activate angiotensin I, a hormone in-volved in regulating blood pressure and volume .