Breathing occurs day and night without stopping. We can survive for a while without food, but we can't breath without more than a few minutes.
Do you know that all living beings need energy to live and that energy is obtained from food? Our body gets energy from food through the process of cellular respiration, performed in mitochondria, with the participation of oxygen gas obtained in the environment.
THE glucose It is one of the main "fuels" used by living cells in respiration. Notice what happens in our cells:
Glucose + oxygen gas -> carbon dioxide + water + energy
It is this kind of phenomenon that goes on and on inside living cells, releasing the energy that ensures the activity of our organs through the work of cells.
Breathing can be understood in two ways:
- The mechanism by which the chemical energy contained in food is extracted in the mitochondria and used to keep the body in activity, this mechanism is cellular respiration;
- The set of processes of exchange of the organism with the external environment that allows the obtaining of oxygen gas and the elimination of carbon dioxide.
We will study breathing according to this last aspect. We will see, therefore, how oxygen gas is absorbed from atmospheric air and reaches our cells; and how carbon dioxide produced during cellular respiration is eliminated from the body.
The respiratory system
The human respiratory system is made up of the following organs in sequence: nose, pharynx, larynx, trachea, bronchi and lungs.
In breathing there are two types of movement: inhalation and exhalation of air. On inspiration, atmospheric air enters the nose and reaches the lungs; on exhalation, air in the lungs is excreted into the external environment.
Air enters our body through two cavities in the nose: the right and left nasal cavities. They are completely separated by a structure called the nasal septum; they communicate with the outside through the openings called nostrils and with the pharynx through the cóanos. The nasal cavities are lined internally by the nasal mucosa. This mucosa contains a set of hair near the nostrils and makes a slimy secretion called mucus.
The hair it's the mucus They act as filters capable of trapping microorganisms and various solid particles that penetrate the nose with air. Therefore, we should breathe in through the nose rather than through the mouth: the nose-inspired air reaches the lungs cleaner than the mouth-inspired air. In addition to being filtered, air is also adequately heated and humidified in the nose.