Construction of the lungs and airways
Lungerne is soft, svampeagtige bodies, which are protected behind the chest bone. There are two lungs, which together fill almost the entire chest. In between the lungs is notably the heart and major blood vessels that go to and from the heart.
Lungerne is enclosed by lungehinderne, usually sticking into the inside of the chest. Between lungehinderne and chest, there is a small amount of liquid, which makes the lungs can move modstandsfrit in relation to the chest wall when breathing. In some diseases, such as. lung cancer , pleurisy , pneumonia or heart failure may amount of liquid increased to more litres, which makes it difficult to breathe.
The air inhaled through the throat and headed down to the lungs through the airways, which begins with the trachea, as the biggest pipes. Luftvejene end up in the lungs as a finely branched piping, head of the indåndede air out in all parts of the lungs.
Luftrøret divides into two large hovedbronkier, as it shares in a number of smaller pipes,bronchial tubes. In bronkievæggene are bruskringe, which ensures that the bronchial tubes always open. When the bronchial tubes are so small that they no longer have a bruskring, called thembronkioler. In both the bronchi and bronkioler there is a ring of muscle, which can adjust the diameter of the pipe. The increased activity of the muscles, which give symptoms, if you have asthma . Krampagtige contractions do here the diameter of the pipe less, so nothing can pass as much air.
Bronkiolerne continue to splinter into smaller and smaller branches, until they eventually end up in some microscopic luftblærer. These vesicles calledalveoler. Henover alveolen there is a network of small thin blood vessels that bring blood in very close contact with the air, which is in the lungs. Thus, the exchange of oxygen and carbon dioxide between the blood and air take place. Væggen in the alveoli is very thin in order to facilitate the exchange of gases, but it also means that they can easily clap along. For that they can stay open, produces a substance calledsurfaktant. Surfaktant increase the surface tension of alveolen, allowing it to withstand pressure.
Lungernes function is to provide the blood (and thus the entire body) with oxygen and to separate carbon dioxide and other waste. This is done at entry and breathing out. The very close contact between lungehinderne and the inside of brystkasssen means that the lungs follows the chest movements. When the chest expanded using vejrtrækningsmuskulaturen, also extended the lungs, and the flow of air into the lungs. This is what happens when a normal inhalation. When the chest sink together again, lu
In addition to supplying the body with oxygen, the lungs also helps to regulate acid-base balance in the body. If there is too much acid, pull up faster and deeper (hyperventilation) to get more carbon dioxide out of the body. Carbon dioxide acts namely as a kind of acid in the blood. If there is too much base, pulled up slower and more shallow to contain the acid. Acid-base-disturbances seen by many different diseases such as. renal failure and diabetes , But actually it is very frequently a disease of the lungs that cause the imbalance. If the lungs can not vent to the normal kuldioxidmængde addition, there will be disturbances in acid-base balance. This is seen, for example. by the deterioration of COPD (Chronic Obstruktiv Lungesygdom, Rygerlunger) .