Respiratory System: Functions

Respiratory
We will discuss:
Respiratory mechanics
Gas exchange in lungs

Respiratory
The energy needed by the body cells to perform their specific functions must, ultimately, the combustion of certain chemicals. These and other biochemical reactions require a continuous supply of oxygen. You can remove CO2 from cellular metabolism.

The general structure of the respiratory system consists of: nose, mouth, pharynx, larynx, trachea, bronchi and bronchioles, ending at saccular structures called alveoli, which are surrounded by a network of capillaries where gas exchange takes place with the blood. 100 m2 is calculated in the contact surface of the alveoli to capillaries. These together with the capillaries form a spongy, elastic dough that is called the lungs.

Respiratory mechanics
The movements that determine the entry of air into the lungs are the inspiration. In this mechanism kicks in the diaphragm and intercostal muscles. The return to its rest position is what we call expiration.

Normally an inspiration increases the thoracic volume in 500 ml of air (air baseline), but if we force the maximum inspiration is able to increase its volume by more than three liters (supplementary air), if we force the expiration we can remove a liter of air more (air extra). A basal amount of air, the complementary and supplementary is known by the name of vital capacity. Respiratory mechanics is governed by the respiratory center. The activity center is subject to multiple influences exerted on the (eg increasing CO2 in the blood.

Gas exchange in lungs
The displacement of a gas through a membrane depends on the permeability of this and part of that pressure on both sides of it. O2 partial pressure when it reaches the alveoli is 100 mm. Hg. Furthermore, the alveolar CO2 pressure is 40 mm. Hg. On the other hand the pressure of these gases in the venous blood to reach the pulmonary alveoli is 40 mm. Hg and 46 mm. Hg respectively. This is where exchange occurs by the alveolar air to arterial blood passes with the same pressure. The amount of O2 that is capable of setting a volume of blood is one hundred times higher than would be expected from the solubility of this gas in the plasma. The reason for this is the particular affinity of hemoglobin (Hb) with oxygen.

*Automatic Translation