Respiratory system Ventolin

In the body, oxygen provides processes mitochondrial and microsomal oxidation, peroxidation of unsaturated fatty acids and oxidase reaction of hydrogen peroxide formation. Its most important role is to provide energy production in cells by oxidative phosphorylation click this link here now buy ventolin online.

Distinguish external (pulmonary) breathing, which provides the supply of oxygen from the environment into the body and removing carbon dioxide from it, and the inner breathing (combination with hemoglobin oxygen, transporting it cardiovascular system to the tissues of oxygen involved in cellular metabolic reactions).

External respiration regulated centers in the medulla and brain bridge. The increase in the blood concentration of carbon dioxide and acidity CSF stimulates exhalation center. Man breathes, and then initiated the inspiratory center. There is a breath. In addition, regulation of respiration receptors take part aortic arch and carotid sinus, an irritant which is reduction of the oxygen concentration in the blood.

Lung ventilation is performed by cutting the muscles of the chest and diaphragm. When muscle contraction, which provide breath, chest expansion occurs. The airway creates a negative pressure, whereby air is sucked into the alveoli. Exhaling normally carried passively: the rib cage collapses, its volume decreases and "waste" the air is expelled.

Tidal volume (UP) in men is 450-800 ml, in women - 400-700 ml. It can be measured by a spirometer or volumetry. However, not all the air that a person inhales, enters the alveoli. Part of it fills the mouth, nose, throat, trachea and bronchi, is not participating in gas exchange. This so-called volume of anatomical dead space (WMD). It is about 30% of the tidal volume (2.22 ml / kg body weight).

In normal respiration occurs with a frequency of 12-18 per minute (BH). Thus, the amount of air that enters the body per minute (minute ventilation, MVL) is Hvl = K • BH (ml).

However, the effectiveness of the external breathing is judged by the alveolar ventilation (AVL). AVL determine how much breathing gas enters the alveoli per minute. It is less than the value of MVL dead space volume AVL = (R - OMP) • BH (ml).

From this formula it follows that breathing at a slower rate and large volume more efficiently than the other way around. Furthermore, it is possible to improve the alveolar ventilation, by reducing the dead space volume. For example, the endotracheal tube or tracheostomy reduces its volume by half.

The process of oxygen in the arterial blood is carried out due to the difference of the partial gas pressures. Thus, at atmospheric pressure 740-750 mmHg and the oxygen content of the air 20-21% of its partial pressure (pO2) of 160-150 mm Hg. at. In the respiratory tract air is mixed with the "waste" gases and water vapor in the alveoli and pO2 is already 110-105 mmHg When the air passes through the alveolar-capillary membrane oxygen partial pressure is further reduced, and in the arterial blood of 95-85 mm Hg At such values ​​rO2a in one liter of blood (plasma) is dissolved 3 ml of oxygen.

The basic amount of oxygen transported in the blood bound to hemoglobin condition. One gram of it can attach 1,34- 1.39 ml of oxygen. Normally arterial blood hemoglobin is saturated with oxygen at 96%. Thus, in terms of hemoglobin 120-140 g / l in one liter of arterial blood oxygen contained 170-190 ml.

With each liter of blood for the metabolic needs of the tissues consumed about 50 ml of oxygen. Venous blood contains 120-140 ml of oxygen, rO2v. - 45-55 mmHg An important indicator of the adequacy of ventilation is the partial pressure of carbon dioxide in arterial blood (pCO2.). Normally it is 36-44 mm Hg Worsening ventilation accompanied by an increase of CO2 above 44 mmHg (Phenomenon hypercapnia). Excessive ventilation, in contrast, promotes the removal of carbon dioxide from the blood. Herein CO2 will be less than 35 mm Hg (Phenomenon hypocapnia).