Gas Exchange in the Lungs - External Respiration

External respiration is the process by which oxygen enters the lungs and carbon dioxide is expelled from the body. Gas exchange occurs in the lungs, where oxygen from the air passes into the blood, and carbon dioxide is removed from the blood to the outside.

When we inhale air, it passes through the nose or mouth and enters the lungs through the trachea and bronchi. In the lungs, air enters the pulmonary alveoli, which are small sacs surrounded by a network of blood vessels. Gas exchange between air and blood occurs in the alveoli.

Oxygen from the air passes through the thin walls of the alveoli and enters the blood. Here it binds to hemoglobin, a protein found in red blood cells. Hemoglobin absorbs oxygen and carries it to the heart, from where it is distributed through the arteries to the organs and tissues of the body.

Carbon dioxide, which is produced in the body's cells as a result of metabolism, enters the blood and is carried to the lungs, where it is expelled during exhalation. Carbon dioxide passes from the blood to the alveoli, where it is expelled along with the exhaled air.

Gas exchange in the lungs occurs due to the difference in pressure between the blood and air in the alveoli. When you inhale, the amount of oxygen in the alveoli is much greater than in the blood, so it passes into the blood. The same picture is observed with carbon dioxide: it is present in large quantities in the blood, so it passes into the pulmonary alveoli for release to the outside.

It is important to note that gas exchange in the lungs is an important process for maintaining the life of the body. Disturbances in gas exchange can lead to serious diseases such as chronic obstructive pulmonary disease and asthma.

In conclusion, gas exchange in the lungs is a complex process that supplies the body with oxygen and removes carbon dioxide to the outside. Understanding this process will help us better understand how our bodies work and how we can take care of our health.