The mechanism of the respiration process in the human
The respiration process
In inhalation process , we take oxygen gas , but in exhalation process , we expel carbon dioxide gas and the water vapor , so the respiration process includes two processes which are the inhalation and exhalation .
When the body is more active , the number of the respiration times increases to obtain more energy needed for all the body activities .
The motion of the chest upwards in the inhalation process , and it is downwards in the exhalation process , and it increases during the walking and there is more increase during running .
The diaphragm is a muscle that separates the thoracic cavity from the abdominal cavity , and it has an important role in the respiration process .
The inhalation process
The inhalation process , the diaphragm muscle contracts and moves down , and the ribs rise upwards , The chest cavity enlarges and the air rich in oxygen gas ( the inhaled air ) enters the two lungs through the nasal cavity ( the nose ) .
The exhalation process
In the exhalation process the diaphragm muscle relaxes and moves up , and the ribs move down , The thoracic cavity becomes narrow and the air rich in carbon dioxide gas and the water vapour ( the exhaled air ) goes out from the two lungs through the nasal cavity ( the nose ) .
The gases exchange inside the two lungs
The exchange of gases occurs between the air existed in the alveoli and the blood capillaries through their thin walls .
The blood leaves carbon dioxide gas ( produced from the burning of the food ) and carries oxygen gas ( from the inhalation process ) , and distributes it all over the body cells , and carbon dioxide gas is ejected out of the two lungs .
The lungs shrink or spread out by the muscles between the ribs of the thoracic cavity and by the diaphragm muscle , and they are free from the muscles , so they can not shrink or spread out lone .