Can You Explain Breathing Mechanisms With The Help Of Examples?

Many animals possess special respiratory mechanisms by which an exchange of gases between animals and the external environment can take place. The breathing motions of an animal consist essentially of two phases as listed below
1.Firstly the taking in of air or water which is called inspiration (or inhalation) and
2.Secondly the giving out of air or water known as called expiration (or exhalation)

There is normally a short pause between the two phases. A simple example of the breathing mechanism of a grasshopper can be quoted to explain the two phases.
In the grasshopper, the breathing mechanism consists of the rhythmic expansion and contraction of the abdominal walls which drive air in and out of the body. During inspiration the abdomen expands. It draws air into the tracheal tubes through the front four pairs of spiracles which are now open, the last six pairs being closed. A short pause follows and exchange of gases between the tissue cells and the air in the tracheoles occurs. During the expiration the grasshoppers abdomen contracts, forcing air out of the body through the last six pairs of spiracles which are now open, the front four pairs being closed this time.