We all know that humans, as well as animals and plants, breathe atmospheric air. Its reserves must permanently be updated, as they are restricted by the lungs capacity.
Holistic breathing process can be divided into extrinsic and internal processes. Extrinsic breathing is the venting of the lungs. And internal breathing is the oxygen consumption by cells and displace of CO2. Satisfaction of needs of the organism in O2 is ensured by 2 physiological systems: 1) respiratory, 2) circulatory.
A person inhales air via the nose, the pharynx, windpipe and bronchial pipes. A human being does about 1000 breaths per hour.
The nasal antrum is the initial phase of the breathing system. This is the emplacement of olfactory receptors. For what do we have two nostrils? Not everybody knows that each nostril is directly related to its lung. Even narrowing of one half of the nose may affect the work of the on the same side. Second, and equally important people sleep at night. And under gravity one nostril is stuffed, so if there was only one hole, we would be constantly spinning. And in the presence of two nostrils, while one is "sleeping" together with us, another is working hardily with dual force.
The pharynx has a funnel-like form and consists of 9 gristles. This is a body segment where sound formation happens. In the laryngopharynx are placed 2 strained vocal cords. A voice`s heights depends on the extent of the cords. The shorter the vocal cords, the higher the frequency of their vibrations and the higher the voice.
The laryngeal antrum is lined with a mucosa that contains receptors. In case of accidental irritation by pieces of food, various solid or liquid substances and gas mixtures, as well as due to inflammatory processes arises a preventive breathing reflex — cough. This sharp reflex is nothing but an exhalation through the mouth. Thanks to cough the laryngeal antrum clears up.
The windpipe is a tube (the length of it is 10-14 cm), it consists of gristle semirings. This tube is parted into two bronchus ramifications.
The Bronchus penetrates into the both lungs. Bronchus, a fraction of the right lung is parted into three ramifications. The one included in the left lung, is separated into 2 offshoots. The smallest components of the bronchial pipes are called bronchioles. They end with pulmonic vesicles which have thin walls that are coated with an exceedingly abundance of blood capillaries of the pulmonic gyration.
The lungs are so-called gas exchange office. They encompass a large number of lung bubbles (about 600 million), which in their turn are imbued with blood vessels. Molecules of O2 enter the blood that carries it to all organs. With blood molecules of carbon dioxide get into the air-breathing vesicles, and a person exhales CO2.