Main and lobe bronchi | Bronchia

Main and lobe bronchi

The right lobe of the lung consists of three lobes. Due to the anatomical proximity to the heart and the resulting narrowness, the left wing consists of only two lobes. Consequently, the two main bronchi, which divide at the so-called bifurcation, branch out into two lobe bronchi on the left and three lobe bronchi on the right.

Their diameter is between 8 and 12 mm. Following the segmental structure of the lung, the flap bronchi divide further. In order to be able to make exact localization descriptions, the lung segments were numbered consecutively.

Segment bronchi

Each segmental bronchus divides into two branches (Rami subsegmentales). These branching occurs up to a diameter of 1mm. Up to this size, the bronchial tubes contain cartilage in their bronchial wall to ensure that they remain open to ensure that breathing air can be conducted. As the bronchi continue to branch out, the frequency of goblet cells and the ciliated epithelium decrease and a ring-shaped muscle system forms under the mucosa. A contraction of this muscle system can lead to a narrowing of the bronchial tubes and thus to the clinical picture of bronchial asthma, for example.

Bronchioles

Due to the loss of cartilage and the ever decreasing diameter, the bronchi are now called bronchioles. These have a single-layered ciliated epithelium, which no longer has goblet cells and can therefore no longer form mucus. The opening of the bronchioles is guaranteed solely by the tension of elastic fibres.

The bronchioles divide into 4-5 terminal bronchioles (Bronchioli terminales). These in turn branch out further into the bronchioli respiratorii, which are 1-3.5 mm long and about 0.4 mm wide. In some places the wall of the bronchioli respiratorii is already formed by alveoli (pulmonary alveoli).

The smallest bronchioles are followed by the alveolar ducts (Ductus alveolares), whose wall consists exclusively of alveoli (pulmonary alveoli). They end in the saccus alveolaris. The small bronchioles (Bronchioli terminales, respiratorii and alveoli) are mainly responsible for the formation of the pulmonary lobules (lobules).

Pulmonary alveoli

The smallest alveoli are surrounded by elastic connective tissue and a fine blood vessel system. By branching out into the smallest alveoli, each of which has a diameter of only about 0.2 millimetres, a very large total surface area is formed, which is responsible for the exchange of gas. Both lungs together have about 300 million pulmonary alveoli, which have a total surface area of 100 square meters.

Diseases of the bronchial tubes

Especially in the autumn and winter months, infections of the respiratory tract are a frequent reason for visiting a doctor. In addition to the nose and throat, the large bronchial tubes are often also affected. During the cold season our immune system is somewhat slower, as our blood circulation is worse in the cold, but the main reason for the more frequent infections in winter is that we are often in closed rooms, usually with many other people, and the air in the room is usually warm and humid.

Bacteria or viruses also like such conditions and therefore multiply faster and can be inhaled more often. The pathogens then reach the lungs via the nasopharynx and begin to attach themselves to the mucosa-lined epithelium of the bronchi. As soon as the pathogens settle in the bronchial tubes, they lead to an inflammation of the mucous membrane of the bronchial tubes, also known as bronchitis.

As a result, the cells that normally ensure a sliding film of mucus on the bronchial tubes start to produce particularly large amounts of mucus to “hold” the pathogens in the mucus. Large quantities of mucus are deposited in the bronchial tubes and this triggers the typical coughing sensation that is typical of bronchitis and is intended to ensure that the excessive mucus can be coughed up. More information about this can be found here Bronchitis Sometimes the mucus in the bronchi is so stuck that medicinal expectorant measures must be taken to loosen the mucus.

In most cases, drugs such as ACC /NAC are used, which can be taken in the form of an effervescent tablet. Just as helpful as the medicinal mucus loosening is the steam inhalation, which can be carried out with or without the addition of a menthol- or eucalyptus-like substance. If the mucus dissolves, it should be coughed up.

The duration of a mucous (also productive) bronchitis is about 7 days. You can find more information about this here Duration of a bronchitis Although 90% of bronchitis is caused by viruses, bacteria can also settle in the bronchi during the course of the inflammation. Typically, after a cough that has already lasted for days, an increased feeling of illness sets in and the mucusy cough becomes increasingly yellowish and tougher and then usually lasts for more than 10 days.

In these cases the family doctor can prescribe an antibiotic, but the administration of an antibiotic does not significantly shorten the duration of the illness. The mucusy bronchial tubes can either be detected by the patient himself or by listening to the lungs at the doctor. In the case of mucusy bronchitis, the doctor hears a typical rattling sound and the mucus movements when breathing.

In rare cases, the pathogens and the inflammation can settle into the deeper sections of the lung (alveoli) and the tissue between them, resulting in pneumonia with sudden high fever and a severe feeling of illness. You can find more information about this here PneumoniaCoughing is a measure taken by the body to remove material (e.g. mucus, pathogens, foreign bodies, etc.) from the bronchi and nasopharynx.

It is often a constant companion of an infection of the bronchi and lungs, but can also occur in the case of protracted sinusitis. Depending on how severe the infection is, the longer and more persistent the cough can also be. A cough that occurs in the context of bronchitis can last up to 14 days.

A cough that is present without any suspicion of infection should be examined more closely by a doctor after three weeks at the latest and, if necessary, by an X-ray of the lungs. A distinction is made between a dry cough and a productive, i.e. slimy, cough. In the past, it was believed that viruses mainly caused a dry cough and bacteria were more likely to cause a productive cough.

In the meantime, however, this strict separation has been abandoned. In the course of bronchitis, a dry cough usually develops first, which then turns into a productive cough with mucus. However, some courses of disease can be accompanied by a severe dry cough alone, which can sometimes last for more than 14 days.

In contrast to the productive cough, the dry cough is usually described by those affected as more tormenting and disturbing. In addition, the ciliated epithelium of the bronchial tubes, which during the day has the task of transporting the smallest dust particles from the lungs to the top, largely stops working in the evening, with the result that an evening cough sets in, which can sometimes last all night and be extremely dry, so that those affected cannot sleep. There are numerous herbal preparations, such as Bronchipret, which are supposed to reduce the coughing stimulus.

Honey has been shown to help very well with coughs. Non-vegetable preparations can also be used, Capval or Silomat® are often used here. The main area of application for these two drugs is the dry cough.

In more severe cases of dry, non-productive irritable cough, an attempt at treatment with codeine can be made. It is important to note here that codeine should only be taken for a limited period of time in order to keep the possible side effects as low as possible. These drugs are called cough suppressants.

They must not be used in combination with cough relievers (such as ACC /NAC), as this can lead to a dangerous accumulation of mucus. Productive and slimy coughs are usually described as less tormenting, as the irritation of the cough decreases rapidly with the coughing up of slimy material. In this case, in addition to inhalation with steam, a medicinal mucus solution with acetylcysteine (ACC akut®) can also be used.

The treatment is intended to cause the mucus that has settled in the bronchial tubes to begin to dissolve. A burning sensation in the bronchial tubes can have various causes. A frequent cause of burning of the bronchi when breathing is inflammation of the bronchial mucosa as a result of infections.

This is not an inflammation of the bronchial tubes or lungs in the classical sense, but rather an irritation of the epithelium due to a long-lasting infection. In most cases, it is not the existing infection that directly causes the symptoms, but the permanent coughing that results from it. A particularly dry and hard cough can lead to irritation of the bronchial mucosa, which the affected person then feels in the form of a strong burning sensation when breathing in and out.

Particularly dry air, mostly in the home, can also cause a burning sensation when breathing. In this case it is very important that the air we breathe is moistened in order not to strain the bronchial epithelium unnecessarily. Inhalation of steam can also help to reduce the burning sensation in the lungs.

The somewhat rarer but more dangerous cause is the inhalation of toxins, which causes severe and prolonged irritation of the mucous membrane in the bronchi. Most often it is the inhaled smoke after an apartment or house fire, which can be extremely toxic and can lead to, sometimes very long lasting, irritation of the bronchial epithelium. After inhaling the smoke, the affected person usually notices a burning sensation shortly afterwards when breathing in and out.

Bronchial tubes can expand and also contract. In the case of bronchitis, they can be normally wide or narrowed by the mucus in them. Due to the mucus, the exchange of oxygen may be reduced and restricted.

A bronchial constriction is particularly pronounced in asthma. This is noticeable in the typical whistling sound of breathing that the patient has during an asthma attack. In this case, the bronchial tubes should be dilated with medication.

This is done primarily by a so-called beta 2 mimetic. There are numerous so-called beta receptors in the bronchial tubes, which ensure that the bronchial tubes dilate when the receptors are stimulated. In addition to adrenaline and other messenger substances, there are also some drugs that lead to a stimulation of the receptors.

Probably the best known drug from this group is salbutamol. It is available in the form of a spray and should be inhaled no more than 2 times a day if necessary. The dilation of the bronchial tubes usually occurs within a few minutes and the effect lasts for about 5-8 hours.

You can find more information about this here Salbutamol Furthermore, adrenaline in the form of an inhaled nebula is also used in hospitals for bronchial dilatation, as adrenaline, as described above, also acts at the so-called beta-receptors. This method of bronchodilatation is mainly used in children’s wards for the so-called “pseudocrupp”. However, since adrenaline can be transferred from the lungs into the bloodstream, this therapy may only be used in hospital.