Dorothy FarrarRespiratory tract
In the narrower sense, the term respiratory tract refers to the air-conducting parts of the respiratory tract. These include the nose , mouth , pharynx , larynx , trachea , and bronchi . Together with the lungs, the airways form the respiratory tract.
Definition
The airways are divided into an upper and a lower respiratory tract. The upper respiratory tract consists of the nose and throat (pharynx). The larynx, trachea, and lungs are part of the lower respiratory tract. The primary function of the respiratory tract is air conduction. Pathogens and impurities are filtered out and the breathing air is humidified and warmed.
Anatomy
The airways start at the nose. This is formed by a bony framework covered with cartilage plates. The bony framework consists of two nasal bones, the maxillary bone and the nasal septum. The three passages in the nose connect to the sinuses, which are inside the skull.
The interior of the nose is lined with mucous membrane . This mucous membrane is covered with small cilia, the so-called cilia. The rear nostril leads to the upper pharynx.
The pharynx can be divided into three areas: the epipharynx (nasopharynx), the mesopharynx (also oropharynx) and the hypopharynx, which is also called the laryngopharynx. The upper area, i.e. the epipharynx, extends from the rear nostril to the soft palate. The middle pharynx occupies the area between the palate and the entrance to the larynx, and the lower pharynx circumscribes the area around the larynx.
The larynx forms the entrance to the lower airways. It consists of five cartilage plates: cricoid cartilage, thyroid cartilage, two pelvic cartilages and the epiglottis cartilage. Together with muscles and ligaments, these form the vocal tract. Between the vocal cords is the glottis (glottis). Three muscles are responsible for the mobility of the vocal cords, one opener and two closers.
The trachea is attached to the larynx. The 10-15cm long tube consists of connective tissue and muscles and is lined with mucous membrane on the inside. Here, too, there are small hairs on the mucous membrane, the so-called ciliated epithelium. The interior of the trachea is reinforced by horseshoe-shaped cartilage braces.
This ensures that the inner diameter always remains the same and that enough air can flow in and out. Movable ring bands between the cartilage braces allow the trachea to be stretched in the longitudinal direction. This allows more air to pass when there is an increased air requirement.
The trachea lies in front of the esophagus and runs from the larynx into the chest cavity. There it divides into two branches, the left and the right main bronchus, at the narrowing of the aorta, also known as the tracheal bifurcation. The Bifurcatio tracheae is located at about the level of the 4th/5th thoracic vertebra. The main bronchi then pull into the lungs. The airways continue to branch out from the two main bronchi via 20 segment bronchi to the fine alveoli ducts.
Function
The main task of the airways is to transport air from the mouth to the lungs. This is where the gas exchange takes place, i.e. carbon dioxide is exchanged for oxygen . The air then exits the lungs through the airways.
As mentioned, almost the entire respiratory tract is lined with mucous membrane covered with fine hairs, the ciliated epithelium. This slimy coating moistens the air you breathe. The mucous membrane of the respiratory tract also has a cleansing function. Dust grains, viruses , bacteria or dirt get caught on the small cilia .
The little hairs are constantly waving in the direction of the throat. As a result, the mucus produced in the respiratory tract, together with the pollutants adhering to it, is transported from the respiratory tract towards the mouth. The mucus is then coughed up or swallowed. In addition, the surface tissue of the respiratory tract is criss-crossed by a dense vascular network. These small vessels constantly give off heat to the air we breathe.
The larynx is of particular importance within the airways. It is important for voice formation and also protects the trachea from food when eating.
Diseases
- Pharyngitis
The main symptoms of diseases of the respiratory tract are coughing, shortness of breath, difficulty swallowing and expectoration. In addition, a runny nose, hoarseness or pain, especially a headache or sore throat, can occur.
The most common disease of the upper respiratory tract is probably rhinitis, the common cold. The cause can be infectious or allergic in nature. The sinuses may be involved. Then one speaks of sinusitis.
But the other structures of the respiratory tract can also become inflamed. Inflammation of the throat is called pharyngitis. This manifests itself in the form of a sore and reddened throat. In the case of inflammation of the larynx (laryngitis), those affected suffer from a barking cough and hoarseness.
Involvement of the larynx in diphtheria is particularly feared. There is a risk of life-threatening suffocation. Bronchitis, i.e. the inflammation of the bronchi, is mainly noticeable through coughing with greenish-yellow sputum.
Cigarette smoke in particular damages the respiratory tract. Smoking is responsible for the development of bronchial carcinoma in almost 90% of cases. A quarter of all malignant tumors in Germany are bronchial carcinomas. Bronchial tumors are among the cancers with the highest lethality.
Hello and welcome to my Health Guide & Encyclopedia! My name is Dorothy Farrar, and I'm the founder and main author of this platform.
My passion for health and wellness started at a young age when I became interested in the connection between the food we eat and the way we feel. This fascination led me to study nutrition and dietetics in college, where I learned about the importance of a balanced diet and the impact of various nutrients on the body.