Human inhalation is achieved by breathing in through the nose or mouth, and then the air travels through the trachea and into the bronchial tubes. WebMD explains that the air is divided between the bronchial tubes that lead to tiny sacs named alveoli attached to bronchioles. The alveoli exchange the oxygen into the surrounding blood-filled capillaries that deliver the oxygen to the heart for distribution throughout the body.Continue Reading
WebMD says that there are over 300 million alveoli in the lungs. After inhalation is complete, the alveoli remove the exchanged carbon dioxide through the exhalation process.
The diaphragm aids the inhalation process. The diaphragm is a dome-shaped muscle. WebMD explains that the diaphragm contracts downward to create a vacuum that helps the air rush into to lungs.
During inhalation, a variety of barriers prevents potentially harmful substances from entering the lungs. WebMD reports that cilia, small hairs in the nose, filter out large particles during inhalation. Cells in the trachea and bronchial tubes produce mucus to stop bacteria, viruses and allergens from passing into the lungs. These mechanisms can be severely damaged by smoke, reducing their effectiveness. Toxins that move beyond these barriers are removed by coughing or through the mucous.Learn more about Organs