the alveoli would collapse.
The alveolar macrophages and pulmonary macrophages or dust cells reside on the internal luminal surfaces of the alveoli, the alveoli, the alveoli ducts, and the bronchioles. They are mobile scavengers that engulf foreign particles in the lungs or blood cells from injuries.
CO2 is a byproduct of the process in cells that uses oxygen to make energy. As oxygen moves out of the alveolus, CO2 molecules pass into it. Then, they are exhaled through your nose or mouth. The surfactant fluid lining the alveoli maintains the shape of each air sac and helps to keep it open so oxygen and CO2 can pass through.
Breath sounds heard during auscultation of the lungs can help diagnose lung disease.
Lung Diseases (Described by Wikipedia & WebMed)
•Asthma is hyperresponsiveness of the bronchi with an inflammatory component. Irritants in the air, photochemical smog, and substances that a person is allergic to can precipitate it. Constriction of the bronchi produces difficulty breathing or shortness of breath. This can lead to a lack of oxygen reaching the body for cellular processes. An inhaler can administer a bronchodilator that soothes the constricted bronchi and re-expands the airways. Herbal inhalers do not have the side effects that most medical inhalers do.
•Diffuse alveolar damage can cause acute respiratory distress syndrome (ARDS) a severe inflammatory disease of the lung.
• Chronic bronchitis is an abundance of mucus produced by the lungs. Mucus occurs when irritants enter lung tissue. In chronic bronchitis, the air passages into the alveoli and the respiratory bronchioles, become clogged with mucus. This causes increased coughing to remove the mucus and is often a result of extended periods of exposure to cigarette smoke.
• Hypersensitivity pneumonitis.
•Cavitary pneumonia is a disease of destroyed alveoli that produce cavities. Damaged alveoli reduce the surface area for gas exchange. Further changes in blood flow can lead to a decline in lung function.
•Emphysema is another lung disease whereby the elastin in the walls of the alveoli breaks down by an imbalance between the production of neutrophil elastase (elevated by cigarette smoke) and alpha-1 antitrypsin (the activity varies due to genetics or reaction of a critical methionine residue with toxins including cigarette smoke). The resulting loss of elasticity in the lungs leads to prolonged times for exhalation, which occurs through passive recoil of the expanded lung. This leads to a smaller volume of gas exchanged per breath.
• Pulmonary alveolar microlithiasis is a rare lung disorder of small stone formation in the alveoli.
• Almost any type of lung tumor or lung cancer can compress the alveoli and reduce gas exchange capacity. In some cases, tumors fill the alveoli.
•A pulmonary contusion is a bruise of the lung tissue caused by trauma. Damaged capillaries can cause blood and other fluids to accumulate in the lung tissue, impairing gas exchange.
• Pulmonary edema is the buildup of fluid in the parenchyma and alveoli usually caused by left ventricular heart failure or damage to the lung or its vasculature.
The lower respiratory tract needs to be well nourished and free of toxins and pollutants for it to communicate and perform in unison the exchange of gases that benefit every other part of the body.