Anatomy of the lungs | Bronchial asthma

Anatomy of the lungs

Anatomy and position of the lungs

  • Right lung
  • Trachea (windpipe)
  • Tracheal bifurcation (Carina)
  • Left lung

In order to understand the processes in the body that underlie the disease asthma, it is necessary to take a closer look at the human respiratory system. Respiration is a very complex process involving several structures. In addition to the lungs, where oxygen is absorbed from the air into the blood, the airways play a major role.

From the mouth or the nose, the air enters the trachea (windpipe). The trachea branches out in the thorax into a right and a left side branch – called the main bronchus – which lead to the left and right lung wing respectively. In the lungs, the two main bronchial tubes branch out further and further, forming smaller and smaller branches that ultimately lead to the alveoli, where gas exchange takes place.

With each branching, the diameter of the air-conducting bronchi becomes smaller. One can imagine the whole thing as an upside-down tree on which the air bubbles hang like apples, which is why the whole thing is also called a bronchial tree. The task of the bronchial tree is not only to lead the air to the alveoli, it also makes sure that the air is warmed, moistened and cleaned when it reaches the alveoli.

To fulfil these tasks, the bronchial system is covered with a special mucous membrane. It is strongly supplied with blood, which leads to a heat exchange between air and blood, is covered with small hairs in which, for example, pollen or dust particles get caught, and it secretes mucus from which the air absorbs moisture during passage. All this literally happens in one breath.

Under the mucous membrane of the respiratory tract there is a ring-shaped muscle layer. It enables the body to regulate the diameter of the bronchi in a targeted manner. A narrowing is called an obstruction here, a widening is called dilatation.

In a healthy state, the body uses this regulation, for example, when it is exposed to a heavy load that requires increased breathing, such as an endurance run/jogging. By widening the bronchial tubes, the air reaches the lungs more easily, which ensures a better supply of oxygen. – The bronchial musculature (3.)


  • The mucosa (2.) swells
  • Increased viscous mucus is produced (1.) – Mucus
  • Mucosa
  • Musculature