The complete respiration and the respiratory mechanics
The respiratory effort has to be oriented towards the posterior inferior base of the lungs, because if the air is displaced in the superior part (as in a costoclavicular respiration), there will not be enough gas exchange, therefore, the blood will be less oxygenated. Individuals with a costoclavicular respiration usually face the problem of cold limbs due to the low oxygenation in the blood. In the upper zone of the lungs perfusion barely happens when being in standing position. On the other hand, very few air arrives to the lower region of the lungs. Furthermore, we have to consider the function of the diaphragm as a second heart, by its hemodynamic capacity, its capacity of moving blood.
The position of the diaphragm is in its relaxed state before the inhalation (dome-shaped position). For the air to enter from the outside, the diaphragmatic muscle has to descend or contract at the same time that it descends, expands and widen its perimeter. This action compresses the visceral mass in the abdomen, facilitating the return of the venous blood to the body.
The importance of correct, natural and free respiratory mechanics resides in the air that enters the lungs that has to be guided in diagonal towards the lumbar zone. As we have already mentioned, the air enters the lungs due to emptiness of pressure (vacuum effect) that occurs when lowering the diaphragm, ensuring that all the sectors of the diaphragm will descend. During inhalation, we have to be conscious of the great descend of the diaphragm, specially, in its posterior region, and have to be conscious of the drive of the air towards the lumbar zone in order to install a natural, free and correct habit of the ventilatory mechanics. It is advisable to do a few voluntary and involuntary conscious respirations.
The whole trunk will expand during the inhalation: the lower, mid and upper zone of the lungs. There will be more absorption of oxygen in the lower zone, as well as the mid zone. This way, the exchange of gasses will be optimal.