What is the structure of our lungs?

The two lungs, arranged in pairs, are further subdivided into lobes. The right lung consists of 3 lobes and 10 segments, the left only of 2 lobes and 9 segments (due to the position of the heart, space is limited here). As a result, the left lung has less space and has evolutionarily developed only 2 lobes.

This also brings another peculiarity. If you swallow something the wrong way, the probability is higher that the object will enter the right lung. You can see this quite well in the photos. This is simply because the right bronchial branch runs somewhat vertically, as an extension of the trachea, and the left branch branches off at an angle, making it less likely that something will fall in there.

Functionally, the air-conducting bronchial system is differentiated from the gas-exchanging alveoli.

Bronchial System (Conductive):

The division of the lung into lobes and segments corresponds to that of the bronchial system. A lobar bronchus supplies a lung lobe with air, just as a lung segment is assigned to the segmental bronchi.

The bronchial tree splits almost 20 times. Main, lobar, segmental, and subsegmental bronchi are distinguished. Accordingly, the division into lung wings, lobes, and segments also takes place.

These sections, however, only serve to transport air from the lungs to the outside and vice versa. But not only that. These sections also have an important filter function. Through various mechanisms, the inhaled air is filtered here, so that pollutants, dirt, germs, and dust don't simply end up in your lungs.

Gas Exchange:

The respiratory bronchioles represent the starting point for gas exchange in the lungs. At their end, the alveolar duct (Ductus alveolaris), a cluster of alveoli can be found (Sacculus alveolaris). The almost 300 million alveoli offer a surface area of 100 m². Interalveolar septa separate the alveoli from each other.

That sounds pretty crazy, right? But it gets even better. The alveoli have a super connection to your blood system and are surrounded by many tiny vessels. This is where the actual gas exchange takes place. The freshly inhaled air is full of oxygen, which your cells need for numerous metabolic processes. On the other hand, your blood is in the vessels, which is enriched with CO2 and contains little oxygen because your cells have already used it.

Due to this gradient and complicated biochemical processes, the CO2 now migrates into the respiratory air and is exchanged for the fresh O2. Your blood now has fresh oxygen again and can continue to supply your cells. You now exhale the old air, thereby exhaling the carbon dioxide.

Ever heard of a pulmonary embolism? This can occur, for example, when a thrombus detaches from the leg and travels up to the lungs. This partially or completely blocks pulmonary vessels. The result? You have filled alveoli, but without blood. As a result, no gas exchange can take place in these areas --> increased dead space. This leads to oxygen deficiency and shortness of breath because your body can no longer exhale enough CO2 and absorb O2.

Smoking and the Lungs

Did you know? Consuming just one cigarette can shorten your lifespan by 7 minutes. With 20 cigarettes a day, this results in a reduction in lifespan of 35 days per year!

Is it really worth the tobacco consumption? Probably not. Smoking is also a risk factor for a wide variety of diseases and tumors.

Pretty much any disease can be caused by smoking. Therefore, it is extremely questionable why smoking is so promoted. Although... Not really, because money obviously plays a major role here, but that's a different topic!

That's it for the short outlook on the lungs. Did you like the article? Let me know and ask your questions in the comments. You can also add suggestions. :-)