explain the mechanism of breathing in humans
Answers
Answer:
The process of taking air into and expelling it from the lungs is called breathing.
The action of breathing in and out is due to changes of pressure within the thorax, in comparison with the outside. This action is also known as external respiration. When we inhale the intercostal muscles (between the ribs) and diaphragm contract to expand the chest cavity. The diaphragm flattens and moves downwards and the intercostal muscles move the rib cage upwards and out. The increase in size decreases internal pressure so air rushes to the lungs. When we exhale the diaphragm and intercostal muscles relax and return to their resting positions. This reduces the size of the thoracic cavity, thereby increasing the pressure and forcing air out of the lungs.
- The breathing in human beings takes place through the organs called lungs. The taking in of air rich in oxygen into the body during breathing is called 'inhalation' and giving out (or expelling) the air rich in carbon dioxide is called 'exhalation'. Both, inhalation and exhalation take place regularly during breathing.