The lungs are made up of different structures that work in coordination to oxygenate the blood and eliminate carbon dioxide.
The lungs are constantly working. They cannot be stopped at any time since it depends on them that absolutely all the cells of the organs and tissues of our body receive the necessary oxygen and we can eliminate carbon dioxide from the blood, the residue that results from cellular respiration and that is toxic to the body.
And this functionality is possible thanks to a perfect coordination between the structures that make up the lungs. Any damage to these parts can affect the ability to breathe, a life-threatening situation. The clearest example is tobacco, whose consumption is linked to all kinds of respiratory diseases.
- We recommend you read: “Human body systems: what are there and how do they work?”
In today’s article we will review the structures that make up the human lungs, detailing their functions and their role in global respiratory function.
How do the lungs work?
The lungs are the vital organs of our body specialized in gas exchange. Their structures are made up of cells designed to allow the passage of oxygen from the air into the blood and the expulsion of carbon dioxide from the blood into the air for subsequent elimination.
The air enters our body through inspirations, either through the nose (preferably) or through the mouth. This air passes, in order, through the pharynx, larynx and trachea, which bifurcates to enter each of the two lungs, where the respiratory function is carried out, which is an automatic act of our body.
When the air is in the lungs, the different structures that we will see next work together to ensure that gas exchange takes place correctly.
The problem is that these structures are very sensitive to toxic substances and the attack of pathogens, which arrive through the air and can colonize some part of our respiratory system.
When the lungs are attacked, either by pneumonia or bronchitis; or if you smoke and lung cancer has developed, the functionality of these vital organs can be affected in a more or less serious way, so it is vitally important to keep our lungs as healthy as possible.
Tips to keep your lungs healthy
Without healthy lungs, the body cannot enjoy vitality. In fact, some lung disorders are life-threatening, as they can make it difficult to obtain oxygen and/or eliminate carbon dioxide.
The main advice is not to smoke . Tobacco kills half of its users. And this, in a world in which there are more than 1,000 million smokers, means that each year some 8 million people die from tobacco or passive smoking, that is, from living with smokers. Tobacco smoke contains more than 7,000 different chemicals, of which 250 are harmful and at least 69 cause cancer.
It is also important to avoid contamination as much as possible . In any case, although it seems that in large cities the situation is alarming, the truth is that at least in developed countries, the levels of air pollution are not dangerous.
Dress warmly and don’t breathe through your mouth. It is important that in the cold months, the air enters the respiratory tract as warm as possible, since the cold weakens the epithelium of the pulmonary structures and makes them more susceptible to problems. Covering the neck area with clothing and breathing through the nose warms the air before it reaches the lungs.
And finally, be physically active and eat a healthy diet. Sport strengthens the lungs, the structures that make them up are healthier and this makes lung function more effective. In addition, fruit, vegetables and fish have been shown to have many benefits to keep the lung structures healthy, which we will see below.
What are the parts of the human lung?
The lungs are the core of the respiratory system. They occupy a large part of the rib cage and the left one is slightly smaller than the right one since it has to share space with the heart.
Be that as it may, both are formed by the same structures that allow the correct exchange of gases. Let’s see them in the order that the air follows from when it enters until it connects with the blood .
1. Trachea
The trachea is the breathing tube that carries air to the lungs. It is a tube that begins in the larynx and descends to approximately the height of the heart, where it bifurcates and each prolongation enters one of the two lungs.
It is not part of the lungs itself but it is important to take it into account since it is what makes the air reach the pulmonary structures.
2. Bronchi
The bronchi are the extensions of the trachea that are already inside the lungs. They branch out as if they were the branches of a tree and carry the air to the rest of the structures of the lungs.
3. Bronchioles
The bronchioles are the finer branches of the bronchi. Each time they become narrower and narrower, although in this way they manage to cover the entire surface of the lungs to ensure that the gas exchange, which occurs at the ends of these bronchioles, happens properly and taking full advantage of the extension of these organs.
In each lung there are about 300,000 bronchioles and they continue to be extensions of the trachea with the function of bringing air to the last structure, the one designed for gas exchange itself: the alveoli.
4. Alveoli
The pulmonary alveoli are small air sacs located at the end of each of the bronchioles, at their ends. It is in them that the lung function itself is carried out, since it is in these alveoli that gases are exchanged.
The alveoli have a wall formed by blood capillaries, thus connecting with the circulatory system. When we inhale air, the alveoli are loaded with oxygen since the other structures work to make it so. Once these small sacs are filled with oxygen, it passes by simple diffusion into the blood through the capillaries.
Red blood cells, which were in the blood transporting carbon dioxide, having more affinity for oxygen, “release” carbon dioxide. And since the alveoli were empty, by simple pressure compensation, this toxic gas goes to the alveoli and then passes through the same circuit but in reverse, being expelled through the expiration process.
This is the way we breathe. It is in the alveoli that oxygen passes into the blood and carbon dioxide is eliminated. The other lung structures bring air to them and, as we will see below, protect them.
Other lung structures
It must be taken into account that the lungs are made up of other structures that, although they are not designed to comply with the gas exchange process, are just as important to guarantee their functionality. We detail them below.
5. Pleura
The pleura is a connective tissue membrane that covers each lung, protecting the structures that we have seen previously. This pleura is covered by a mucous substance that allows the lungs to always remain lubricated.
It is the support structure for the lungs. It helps absorb shock so internal structures are not damaged, prevents rubbing against the rib cage, and allows the lungs to expand and contract during the breathing process.
6. Lung lobes
The pulmonary lobes are the segments into which the pleura is divided. They are a kind of folds in this membrane that are essential for the lung to expand and contract without forcing the lungs too much.
The right lung is divided into three lobes: upper, middle, and lower. The left one is smaller, so it is only divided into two: lower and upper.
7. Diaphragm
The diaphragm is a structure that is not part of the lungs but is very important for them to fulfill their function. It is a dome-shaped muscle located below the lungs that contracts during inspiration. In this way, it helps the lungs to carry out the necessary movement to fill with oxygen.
Likewise, it relaxes during expiration to help the lungs get rid of carbon dioxide. Therefore, it is a vital muscle for proper lung function and also provides structural support for the lungs to stay in the right place.
Bibliographic references
- Tomashevsky, J.F., Farver, C.F. (2009) “Anatomy and Histology of the Lung”. Dail and Hammar’s Pulmonary Pathology.
- Less, N., Soni, N. (2014) “Respiratory Physiology”. Clinical Intensive Care Medicine.
- Wahlstedt, R. (2019) “Anatomy of the Lung”. Liberty University.
To the classic question “what do you do?” I always answer “basically I am a psychologist”. In fact, my academic training has revolved around the psychology of development, education and community, a field of study influenced my volunteer activities, as well as my first work experiences in personal services.