The word “pulmonary” is often related to the respiratory system and primarily to the lungs. This is due to the fact that the word pulmonary actually comes from the Latin word “pulmonarius” which means “of the lungs”. You may have also heard the word “pulmo” being associated to the lungs. Again, it is because the word “pneumo” comes from a Greek word which means lungs.

Looking Into The Lungs

Oxygenated bloodCredit:

Lungs are known to be one of the most important organs as it facilitates respiration. There are actually two lungs located in the chest. The main function of the lungs is to transport oxygen through the bloodstream to different parts of the body.  They are also the ones responsible for releasing carbon dioxide from the bloodstream as well. These exchange of gases are necessary for the maintenance of normal body functioning and such exchange can also benefit the environment due to the fact that the carbon dioxide released by the lungs are used by plants for their own processes as well.

Passage Of Air Through The Lungs


The air that enters the body passes through several organs primarily involving the respiratory system before it could finally end up in the depths of the lungs. First of all, the air will pass through the mouth or the nose, the two main entrances of air in our body, After they pass through the nose or mouth, they will go to the oropharynx and the nasopharynx. After this, they have to go through the larynx, trachea and eventually starting through the system of the bronchi and the smaller bronchioles. The air will finally end up reaching the alveoli or the small sacs that can be found at the lower end of the lungs. The alveoli are the specific parts of the lungs where carbon dioxide and oxygen exchange takes place.

The act of getting and removing air from the body is actually natural function mediated by muscular action. This process of taking in and removing air from the body is known to be the process of ventilation. This is of course controlled by our brain and in situations when our air source is compromised, we perform the voluntary action of taking in much air as necessary in addition to the normal involuntary action of our body when it comes to ventilation.

If you will closely observe the structure of the human lungs, you could be able to see that it is made of soft tissue thus giving it a soft and spongy texture. It also has its epithelium having a huge surface area within the lungs as compared to that of the outer surface. The main body function of breathing is primarily involving the lungs. The act of breathing is actually driven by the diaphragm located at the lower part of the trunk or the thorax. As the diaphragm contracts, it pulls the bottom of the pleural cavity where the lung can be found. When this happens, the volume of the lung increases and the pressure inside is decreased thus more air is allowed to enter the lungs. This will facilitate the flow of air into the mouth and the nose after which it flows through the pharynx, larynx and trachea. The air can eventually go into the main bronchi which will further divide into its smaller branches. During breathing, the expiration of air is considered to be passive and there is no contraction of muscles due to the fact that the diaphragm is relaxed.

First of all, the air can start passing through the nasal or oral cavity. The nasal cavity can serve as a filter for air with its nasal hair. The nasal hair makes sure that the air is well prepared by taking off unnecessary particles included in it. Through this process, the lungs could be able to receive clean and well-filtered air. After the main entrances of air, there is the oropharynx and the nasopharynx. This is eventually followed by the trachea which leads to the division of the two main bronchi which serves as the main entrance to the lungs itself. The bronchi will continue to branch within the lungs. They will further divide into smaller structures until they become bronchioles. These are the smaller structures that arise from the main bronchi. The bronchioles will eventually lead into the even smaller alveolar sacs. These alveolar sacs in turn, are made of the smallest components of the respiratory system known as the alveoli. If you are to describe the alveoli, it actually looks like a bunch of grapes. Each piece of alveolus is wrapped in blood vessels to ensure its adequate blood supply. As what have been previously stated, this is also known to be the site where the exchange of gases actually takes place.

The Flow Of Blood Into The Lungs

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When it comes to the blood supply, you should know that the deoxygenated blood coming from the heart is actually pumped to the lungs by means of passing through the pulmonary artery. In the lungs, the blood is being oxygenated through the means of diffusion. Aside from this, carbon dioxide is taken from the hemoglobin content of the red blood cells as well. If this happens, the oxygen rich blood will already return to the heart by means of pulmonary veins so that it can be eventually pumped out for the systemic circulation. On the other hand, the carbon dioxide left in the lungs will be eventually released from the human body.

Differences Between The Two Lungs

Lung DifferenceCredit:

There are two lungs located each on the side of the heart. They can be similar in appearance but if you closely observe, you can definitely notice the differences. First of all, the right lung contains three lobes as compared to the left lung which only has two. These lobes are considered to be partitions of the lungs brought about by fissures. The lobes are considered to be the largest division of the lungs because it can still be divided into segments and eventually into small lobules. The lobules are known to be divisions of the lungs in hexagonal shape considered to be the smallest division of the lungs that can be seen by the naked eye. Another difference of the two lungs aside from the lobule is the fact that the right lung is known to have shorter, wider and even less curved bronchi as compared the right lung. These are just some of the distinct differences between the two lungs.

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