explain the mechanism of breathing in humans
Answers
Answer:
Breathing is the physical process of inhaling oxygen and exhaling carbon dioxide. The mechanism of breathing involves two main processes: inspiration and expiration. Inspiration occurs when the diaphragm and the external intercostal muscles contract. Expiration occurs when the diaphragm and the intercostal muscles relax.
The process in which air moves in and out of the lungs is known as breathing.
The air which we breathe in and out of the lungs varies in its pressure. So basically when there is a fall in air pressure the alveolar spaces falls and the air enters the lungs (inspiration) and as the pressure of the alveoli within exceeds the atmospheric pressure, the air is blown from the lungs (expiration). The flow rate of air is in proportion to the magnitude of the pressure difference.
The breathing mechanism involves two processes:
Inspiration
Expiration
In the process of inspiration, there would be a contraction of muscles attached to the ribs on the outer side which pulls out the ribs and results in the expansion of the chest cavity.
Later, the diaphragm, contracts, moves downwards and expands the chest cavity resulting in the contraction of the abdominal muscles.
The expansion of the chest cavity produces a partial vacuum which sucks air into the lungs and fills the expanded alveoli.
Expiration
The expiration process is considered once after the gaseous exchange occurs in the lungs and the air is expelled out. This expulsion of air is called expiration.
During this process, muscles attached to the ribs contract, the muscles of the diaphragm and the abdomen relax which leads to a decrease in the volume of the chest cavity and increases the pressure of the lungs, causing the air in the lungs to be pushed out through the nose.