Describe the breathing process.
less than 200 words.
Breathing is the process by which humans and other living beings take in oxygen from its environment and release carbon dioxide. There are many different ways in which different animals breathe. Here I will describe the process of breathing in humans.
The main organs used by human for breathing is lungs. There are a pair of longs located in chest. Each lung contains millions of small air sacks called alveoli.
The lungs sucks the air from the environment through the process of inhalation (breathing in) by the action of contraction of diaphragm and chest muscles. This causes the lungs to expand and air is sucked in. The air enters the lungs from nose and mouth through the wind pipe (trachea). This air, which contains about 20% oxygen and 0.3% carbon dioxide comes in contact with blood capillaries in alveoli, causing blood to absorb oxygen from the air inhaled and release carbon dioxide.
The process of inhalation is followed by the process of exhalation (breathing out) in which the diaphragm and chest muscles relax. With this the air in the lunges is forced out of the lungs. This exhaled air contains about 17% oxygen and 5% carbon dioxide. This completes one cycle of breathing.
These cycles of inhalation and exhalation continue one after the other.