Respiratory

Air must constantly move in and out of the lungs to release oxygen and remove carbon dioxide. This is achieved by inhalation and exhalation. Taking in air is called inhalation, and exhalation is called exhalation. A normal person breathes in and out 15-20 times per minute.

With each inhalation, 500 cubic centimeters of air enter the lungs and with each exhalation, the same amount of air leaves. No matter how hard the effort is, the air cannot be completely expelled and some air remains in the alveoli. Therefore, since the lungs never run out of air, gas exchange continues uninterrupted. Normally, the 500 cubic centimeters of air taken in is called exhaled air. When a deeper breath is taken, an additional 1500-2000 cubic centimeters of air enter the lungs, which is called supplementary air. If more air is forced out than the normal 500 cubic centimeters, an additional 1500-2000 cubic centimeters of air leave the lungs, which is called reserve air. The total of all these amounts of air amounts to 3500-4500 cubic centimeters, which is called the vital capacity of the lungs. No matter how hard the effort is, there is a certain amount of air that can never be expelled from the lungs. This is called residual air and is approximately 1000-1500 cubic centimeters.

The lungs do not have the ability to move on their own. Their expansion and contraction, in other words, taking in and out air, occur through the action of a number of active muscles. One of the muscles that plays a role in respiration is the diaphragm muscle. In order for air to enter the lungs, the air pressure in the lungs must be less than the air pressure outside. This is only possible by expanding the rib cage and therefore the volume of the lungs. The expansion of the rib cage is possible by lifting the ribs and contracting the diaphragm muscle. The diaphragm, a muscle that separates the body into the chest and abdominal cavities, rises in a dome shape towards the chest cavity when not breathing. The rib cage expands from bottom to top as a result of the contraction of the diaphragm muscle during inhalation and the dome part being pulled down slightly. The lungs, which do not leave the rib cage during expansion, expand together with the rib cage as a result of the ribs being lifted by special muscles, and the pressure of the air in the lungs decreases. Thus, the external air, which remains high in pressure, enters the alveoli through the respiratory tract. While the diaphragm and ribs return to their original state, the volume of the lungs decreases, the pressure of the air inside them increases, and as a result, the air is expelled.

The respiratory system, blood and circulatory systems work together to perform the task of breathing. Breathing occurs in two ways:

1. Internal respiration: The exchange of oxygen and carbon dioxide that occurs within cells, that is, the biological combustion event, is called internal respiration. Biological combustion event constitutes the main respiration in organisms. Internal respiration provides the energy necessary for all vital events to continue in cells. Internal respiration also means the biological combustion of energy-laden compounds, especially carbohydrates and fats, that come to the cell and the release of the energy they are loaded with for vital events.

2. External respiration: The breathing that takes oxygen from the air through the lungs and gives it to the blood and removes carbon dioxide from the blood through the lungs is called external respiration.

Respiratory event: Alveoli have thin walls made only of epithelial tissue. The outer surfaces of the alveoli walls are surrounded by arterial and venous capillaries like a network. Carbon dioxide-laden blood constantly comes to the outer surfaces of the alveoli through the pulmonary artery. On the other hand, oxygen-rich air enters the alveoli through the airways and gas exchange occurs between the air and the blood inside them through their thin walls. The gas exchange surface formed by the alveoli, which are approximately four hundred million in number, in the lungs is quite large. During a deep breath, the surface of the alveoli, that is, the respiratory surface, increases to one hundred square meters in total. This surface is approximately fifty times the body surface of a person.

The amount of carbon dioxide in the blood that has reached the outer surfaces of the thin walls of the alveoli is much higher than the air inside the alveoli. The amount of oxygen is the exact opposite. Due to this difference in gas density, a transition occurs. The carbon dioxide brought by the plasma of the blood and the red blood cells passes into the alveoli through the alveoli wall. At this time, the oxygen in the alveoli also passes into the blood and is chemically bound by the hemoglobin in the red blood cells of the blood. The hemoglobin, which contains iron, turns into oxyhemoglobin. The blood, which is rich in oxygen on the surface of the alveoli, is collected by the venous capillary network and brought to the left atrium of the heart via the pulmonary vein. As a result of the pumping of the heart, the oxygen-rich blood is spread to the left ventricle, and from the left ventricle through the aorta and its branches to all the cells of the body. The red blood cells that approach the cells give the oxygen they have carried from the lungs to the cells and take the carbon dioxide, which is the biological combustion residue in the cells, and other waste materials.

There are many different respiratory diseases. When the nasal mucosa becomes inflamed and swollen, a cold occurs. The nasal cavity is connected to various bones such as the frontal bone, the palatine bone, and the upper palate bones. There are small cavities (sinuses) inside these bones. Sometimes, if the nasal mucosa becomes inflamed, the inflammation fills the sinuses and causes sinusitis. Some people's nasal mucosa is extremely sensitive to pollen. Such people catch a type of allergic rhinitis called spring fever during the pollination period of flowers. In some cases, inflammatory diseases seen in the nasal mucosa can be transferred to the regions related to the respiratory tract. Accordingly, pharyngitis, pharyngitis; laryngitis, laryngitis; tracheitis, and bronchitis are mentioned. Pulmonary tuberculosis and tuberculosis can occur in resistant lungs.