Without food a person can live for several weekswithout water - only a few days, and without air, after 4 minutes, brain cell damage occurs and further death. The respiratory system of our body is a truly wonderful device.
How does the human respiratory system work?
The respiratory tract consists of interconnecteda walkways and tubules. What path does air take before it reaches the lungs? This long journey begins when air enters the throat through the mouth or nose. As you know, in the pharynx respiratory and digestive paths intersect. To prevent food or liquid from swallowing in the respiratory tract, there is a small lid known as the epiglottis, which covers the entrance to them.
Through the larynx past the vocal cords airrushes into the trachea or respiratory throat (its length is 12 cm). Over its entire length, the trachea is reinforced with approximately twenty horseshoe shaped cartilages. At the end of the trachea is divided into two tubes of 2.5 cm - the main bronchi. They enter the right and left lung, where they branch out into many bronchi.
Branching of the bronchi resembles the structure of the treewith a trunk, branches and thin branches and twigs. Every new branch is getting thinner. The air is directed into small branches - small vessels with a diameter of up to 1 mm, called bronchioles.
Then the air fills 300,000 even smallerchannels - sacs of the alveoli. They are clusters located in the lungs and look like the smallest bubbles. This completes the tree respiratory system and the air reaches its final destination.
The structure of the lungs - the main organ of the respiratory system
It is worth mentioning how perfectly located inOur bodies are light - on both sides of the heart. The right lung includes three lobes, and the left - two. This anatomy helps surgeons: the respiratory system will work quite successfully even after some sore lung has been removed.
Lung tissue resembles the structure of a sponge.Its lower part of the lungs adjacent to the diaphragm. This strong muscle septum separating the chest cavity from the abdominal cavity. The diaphragm is called the most important breathing muscle, it participates in the work of constant expansion and constriction of the lungs.
Each lung is covered by a thin shell - the pleura.The inner side of the chest is also covered with a similar shell. Between the layers is a lubricating fluid. Due to this structure, both the lungs and the chest slide freely during breathing.
The final threshold of inhaled air
When the air reaches the alveoli, itadjoins to a network of the thinnest blood vessels - pulmonary capillaries. Red blood cells (red blood cells) can pass through the capillaries only one at a time, so narrow are their diameters. Through the thinnest walls (0.5 microns) carbon dioxide passes into the alveoli. Oxygen leaves the alveoli, absorbed by red blood cells.
Only three quarters of one second red cellblood remains in the capillaries. In this short time, carbon dioxide and oxygen have time to swap places. This amazing gas exchange process is called diffusion. The blood, enriched with oxygen, enters the pulmonary veins and reaches the left half of the heart and is pumped from there throughout the body.
Imagine it takes only a minute for all the blood to complete this complex respiratory relay!
Breath is an automatic system.
Healthy lungs automatically about 14once a minute, air is drawn in while breathing. Although this automation can be deliberately suspended by holding your breath, it can only be done for a couple of minutes. For example, this is necessary during diving or in a gassed room, but after this time, according to the ingenious program of their genius, the lungs will inevitably return to automatic operation. Where is the control center of this "automatics"? In the brain stem, special receptors monitor the content of carbon dioxide in the blood. When the level exceeds the allowable mark, the brain will send signals through a network of nerves and the respiratory muscles will be forcibly activated by the body.
What a miracle this is - the respiratory system presented to us by the Creator!
