Diseases that affect the lungs. The lungs are the organs responsible for breathing. Examples of respiratory diseases are infections (pneumonia), tuberculosis, damage to the lungs from cigarette smoking, and lung cancer. Many respiratory diseases are treated with medical therapy, but some may require surgery.
Respiratory or lung diseases include asthma, pneumonia, tuberculosis, lung cancer, and many others. Respiratory diseases are among the most prevalent and the most rapidly expanding in prevalence worldwide. Respiratory illnesses are health problems of the lungs or airways that sometimes make it difficult to breathe. They can either last a short amount of time, like with a cold, or they can last for years. Respiratory illnesses can be caused by a variety of indoor pollutants.
The respiratory system is the biological system of any organism that engages in gas exchange. Even trees have respiratory systems, taking in carbon dioxide and emitting oxygen during the day, consuming oxygen and producing carbon dioxide at night. 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. Air enters the body through the nose and mouth and travels down the trachea, through the bronchial tubes, and finally into the lungs. Once in the lungs, the air is drawn into an enormous number of thin-walled sacs richly supplied with capillaries. The exchange of oxygen and carbon dioxide in the blood takes place in these tiny sacs.
Lung diseases are conditions that occur within the lungs. The lung is an organ belonging to the respiratory system and interfacing to the circulatory system of air-breathing vertebrates. Its function is to exchange oxygen from air with carbon dioxide from blood. The process in which this happens is called "external respiration" or breathing. There are also nonrespiratory functions of the lungs. The human lungs are paired organs, located on either side of the heart and occupying a large portion of the chest cavity from the collarbone to the diaphragm. Air enters the body through a series of passages, beginning with the nose or mouth. It travels to the chest cavity through the trachea, which divides into two bronchi, each of which enters a lung. The bronchi divide and subdivide into a network of countless tubules. The smallest tubules, or bronchioles, enter cup-shaped air sacs known as alveoli, which number about 700 million in both lungs. Each alveolus is surrounded by a net of capillaries. As blood flows through these vessels, carbon dioxide passes into the alveoli, and oxygen diffuses into the bloodstream. The capillaries are part of a vast network of pulmonary blood vessels that connect the lungs directly to the heart via the large pulmonary arteries and veins. The alveoli are clustered in groups, or lobules, and the lobules are clustered into lobes.
Lung disease is any disease or disorder where lung function is impaired. There are three major physiologic categories of lung diseases. Obstructive lung disease is a decrease in the exhaled air flow caused by a narrowing or blockage of the airways, such as with asthma, emphysema, and chronic bronchitis. Restrictive lung disease is a decrease in the total volume of air that the lungs are able to hold. Often, this is due to a decrease in the elasticity of the lungs themselves or caused by a problem related to the expansion of the chest wall during inhalation. Another category of lung disease is a defect in the ability of the lung's air sac tissue to move oxygen into a person's blood. Defective lung diseases decrease the lung's ability to move oxygen from its air sac tissues to the blood. Most lung diseases actually involve a combination of these categories, such as emphysema, which involves both airflow obstruction and oxygenation problems.
