1. FUNCTION.
is the unit responsible for capturing the oxygen (O2) of atmospheric air and release carbon dioxide (CO2) produced during cellular respiration.
2. PARTIES.
The human respiratory system consists of the airways, where are located the nostrils, pharynx, larynx, trachea and both bronchi and both lungs.
The bronchus to enter the lungs appearing bronchioles branch, which branch out again to form the lung lobes, within which are located the pulmonary alveoli, responsible for gas exchange.
§ The Larynx is the organ that produces the voice, containing the vocal cords and a kind of cap called the epiglottis so that food does not pass through the airways.
§ The trachea is a tube formed by about twenty rings of cartilage that keep it always open, is divided into two branches, the bronchi.
§ The bronchi and bronchioles are the various branches of the interior of the lung, ending in sacks called alveoli which have in turn a smaller bags or pulmonary vesicles are surrounded by a multitude of capillaries through which blood and purified and gas exchange takes place. §
Lungs are two reddish spongy masses, located in the chest on both sides of the heart, the right has three parts or lobes, the left has two parts.
§ The pleura is a double-walled membrane surrounding the lungs.
3. OPERATION .
The process of entry and exit of air from the lungs is called respiration. It is possible to distinguish several parts:
1. Inspiration. Marks the entry of atmospheric air into the lungs. As the atmospheric air moves through the airways, they are heating, moistening and filtering to make it reach the lungs where gas exchange occurs in the right conditions. It is therefore necessary that the intercostal muscles to contract and raise the ribs and sternum, and diaphragm descends. This increases the capacity of the thorax, the volume of air that can be stored. So the air flows from outside to inside of the lungs due to this pressure difference.
2. Gas exchange. Takes place in the alveoli that are lined by a thin capillary network. In this exchange, the oxygen in higher quantities in the atmospheric air passes through the alveoli into the blood, and this carbon dioxide into the air atmosphere. This happens because the pressure difference between the different gases.
3. Expiration. Here the external intercostal muscles relax and lower the ribs and sternum and the diaphragm rises. This decreases the ability of the rib cage, increasing the pressure inside the lungs and causing them to contract and, therefore, that CO2-rich air out
4. LUNG CAPACITY
§ Tidal volume (VC). Is the volume of air that normally enters or exits an inspiration in a breath. In men is 0.5 liters. §
inspiratory reserve volume (IRV). Is the volume of air entering over a forced inspiration. In men is 3 liters. §
reserve volume expiratory (VRE). The volume of air leaving more of a forced expiration. In men is 1 liter. §
vital capacity (VC). The volume of air that can be exhaled after a forced inspiration. Is the sum of the previous three volumes (VC + VRI + VRE = CV). In men is 4.5 liters. §
residual volume (RV). Is the volume of air that is always within the lungs. In men is 1.5 liters. §
total lung capacity (TLC). Is the maximum amount of air the lungs can accommodate. The man is 6 liters.
5. THE RESPIRATORY AND PHYSICAL ACTIVITY .
practice activity brings physical need for more oxygen to muscles. Thus, pulmonary ventilation increases almost in direct proportion to the work done.
Given this need for oxygen, the lungs are adapted in two ways. First respiratory rate increases going from around 12 in normal conditions until nearly double in full exercise. Secondly, there is also an increase in the depth of respiratory movements, thus increasing the volume of air breathed is normally 0.5-liter
The respiratory adaptations to exercise are occasional, ie, once the activity has ceased physics that brought the greater need for oxygen, respiratory function returns to normal. However
adaptations are maintained over time, chronic adaptations. To achieve this kind of adaptation is necessary to practice physical activity for a long time, many months or even years. Indeed, shortly after (2-3 months) to stop exercising, these adaptations begin to miss.
chronic adaptations of the respiratory system are:
- Increases efficiency of the respiratory muscles, which increases the thoracic cavity and the lungs are able to contain more than atmospheric air.
- Increases the elasticity of the rib cage, causing the same effect.
- Increases the alveolar surface, facilitating gas exchange.
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