Respiratory tract
Overview
The term respiratory tract is an umbrella term for all organs involved in breathing. Functionally, a distinction is made once again within the respiratory tract between organs that are responsible for the conduction of the air (so-called air-conducting organs) and those that are ultimately responsible for the actual breathing itself (so-called gas exchange, in which the blood is supplied with fresh oxygen and the oxygen used in the body is exhaled in the form of carbon dioxide).
Another type of classification can be made according to the location of the various organs. A distinction is made here between the upper and lower airways. In addition to breathing, the respiratory tract is also involved in the formation of the voice.
construction
According to the functional classification, there are the sections of the respiratory tract that are responsible for conveying the air to the sections of the respiratory tract where actual breathing takes place. Air-conducting organs are those Nasal cavity, the Larynx, the windpipe and the Bronchi with their branches. The actual respiratory organs, on the other hand, are those smaller end branches the bronchi in which the actual breathing, namely the gas exchange, takes place (so-called. Bronchioli respiratorii and the alveoli).
The division of the respiratory tract into the upper and lower airways is based on the location. Are they lying above the larynxIf they belong to the upper respiratory tract, they lie underneath, they belong to the lower respiratory tract.
The respiratory tract begins at the nasal cavity. A distinction is made between a left and right nasal cavity, that of the Nasal septum (Septum nasi) are separated from each other in the middle (medial). In addition, the nasal cavity houses the human olfactory organ. The connections to the Sinuses lie in the lateral nasal walls. Infectious diseases of the nose can find their way into the sinuses here and become uncomfortable there Sinus infection lead that with purulent discharge from the nose, difficulty breathing through the nose and a feeling of pressure in the head.
There is an opening to the rear in the nasal cavity so that a connection (the Choans) to the pharynx and the air can be passed on. The function of the nasal cavity in breathing is also in the warming the inhaled air to a temperature that about 1 degree Celsius differs from body temperature. Apart from that, the air through the hair located in the nasal cavity is already rough of any possible Dirt particles cleaned. In terms of its location, the oral cavity also belongs to the respiratory tract, because air can also be inhaled through the oral cavity.
As the next station in the respiratory tract, it closes throat (Pharynx) to the nasal cavity. There are three sections in the throat. A upper Section, the so-called Nasopharynx, which is the connection to the nasal cavity middle Section with connection to the oral cavity (Oropharynx) and a lower Section that Laryngopharynxthat connects to the Trachea and esophagus represents. Seen in this way, it is both a respiratory and a food pathway and its function is to convey the inhaled air from the nasal cavity into the trachea and to convey the food from the oral cavity into the esophagus.
At the lower end of the pharynx it closes Larynx (Larynx). The larynx is made up of muscles and parts of cartilage. It separates the trachea from the esophagus and ensures that the food actually consumed actually enters it Esophagus and not accidentally into the windpipe where they might block the airway. If this happens anyway, there is a risk of not being able to breathe and choking on swallowed food.
The next section of the respiratory tract is the pharynx windpipe (Trachea). She is part of the air conduction system and establishes the connection to the Bronchi of the lungs. She is about 10-12cm long, lies in front of (ventral) the Esophagus (Esophagus) towards the abdomen and can best be described as an elastic tube that connects below the larynx (larynx). The windpipe is shaped like a horseshoe Cartilage braces stabilized, which ensure that the Trachea by inhalation resulting negative pressure does not collapse. The inside of the windpipe is covered with a surface, the one thin film of mucus produced, which ensures that small dust particles and dirt, which are transported with the inhaled air, get caught and can be carried upwards by the cough reflex. In addition, there are cells in the surface that are called Sensors serve for the substances contained in the air. The windpipe branches at the level of the 4th / 5th Thoracic vertebra in the left and right main bronchuswho have favourited Bronchi principales.
This closes as the next section of the respiratory tract Bronchial system at. It is an umbrella term for those in the lung trending airways. The bronchial system can be described as itself always branching out Understand the system of tubes in the so-called Alveoli (Alveoli) end where the actual gas exchange takes place. Here, too, a distinction is made between an air-conducting part that transports air to the alveoli and the part that is responsible for gas exchange. The bronchial system begins with the two main bronchi.
The right main bronchus branches off the trachea at a slightly steeper angle and supplies the right lung. The left main bronchus accordingly ventilates the left lung. The slightly steeper angle on the right side ensures that inhaled foreign bodies mainly get into the right main bronchus. Since the heart Located on the left side of the torso, the left lung is slightly smaller than the right. That's why from the left main bronchus only 2 branches come off, the so-called Lobe bronchi (Bronchi lobares), while from the right main bronchus 3 branches go off. These branch out into segments, analogous to the organization of the lungs Segment bronchi (Segmental bronchi). For the sake of clarity, these are provided with numbers. Right there 10 segment bronchi, left 9. This numbering is universal. This means that the numbering of the bronchus is the same for every person, so that it is easier to describe which bronchus is meant, e.g. when it comes to explaining where one is Tumor or foreign body is located.
The next smaller branch becomes Lobular bronchus (Bronchus lobularis) called. With each further branching, the diameter of the bronchial tubes continues to decrease. This is followed by the so-called Bronchioli at. These represent the first section of the bronchial tree, the none cartilage contains more. The diameter of this section is with 1 millimeter already very low. At the end of the bronchioli, these branch into 4-5 terminal bronchioles on (Terminal bronchioles), which represent the end of the air-conducting section of the respiratory tract.
This is followed by the part of the lungs that is responsible for gas exchange. The so-called Alveolar ducts (Ducti alveolares) through which the inhaled air enters the Alveolar sac (Sacculi alveolares), which comes from several Alveoli (Alveoli) are formed. this is the Terminal of the respiratory tract. Gas exchange now takes place in the alveoli, during which fresh oxygen is transferred into the blood and used oxygen is released in the form of CO2 so that it can be exhaled.
