Respiration is achieved through the mouth, nose, trachea, lungs, and diaphragm. Oxygen enters the respiratory system through the mouth and the nose. The oxygen then passes through the larynx and the trachea. The trachea is a tube that enters the chest cavity. In the chest cavity, the trachea splits into two smaller tubes called the bronchi. Each bronchus then divides again forming the bronchial tubes. The bronchial tubes lead directly into the lungs where they divide into many smaller tubes and connect to small sacs called alveoli. The average adult's lungs contain about six hundred million of the air filled sacs that are surrounded by capillaries. The inhaled oxygen passes into the alveoli and then goes through the capillaries into the artery vein and into the blood. The used oxygen in the blood from the veins releases its carbon dioxide into the alveoli. The carbon dioxide follows the same path out of the lungs when you exhale. .
The diaphragm's job is to help pump the carbon dioxide out of the lungs and pull the oxygen into the lungs. The diaphragm is a layer of muscles that is across the bottom of the chest cavity. As the diaphragm contracts and relaxes the person breaths. When the diaphragm contracts, oxygen is pulled into the lungs. When the diaphragm relaxes, carbon dioxide is pumped out of the lungs. .
DISEASES.
The bronchi are air passages connecting the trachea with the sacs of the alveoli where oxygen is taken up by the blood. Bronchitis is an inflammation of the bronchi causing excessive mucous production and swelling of the bronchial walls. .
Many people suffer a brief attack of acute bronchitis with fever, coughing and spitting when they have a severe cold. Chronic bronchitis is the term applied when this coughing and spitting continue for months and return each year. These generally last longer each time. Obstruction to air flow in the air passages is caused by swelling of the bronchial wall and the presence of .