The trachea and tracheoles of grasshoppers are distributed in different parts of the body like a network and exchange gaseous substances. As their blood does not contain oxygen, it does not play any role in respiration. Inhales and exhales mainly through the trachea. Inhalation and exhalation processes are discussed.
1. Inspiration: Abdominal segments expand with muscle expansion. As a result, the volume of the inner cavity of the trachea increases. At this time the first four pairs of trachea open. Air containing oxygen from the environment enters the tracheal cavity through the trachea. Later oxygen from trachea reaches tracheole. Due to the thin wall of the tracheole, oxygen enters the body cells in the process of diffusion.
2. Expiration: CO2 is produced as a result of metabolism in body cells. The CO2 produced enters the tracheole in the process of diffusion. Then CO2 from the tracheole enters the trachea. During this time muscle contraction occurs. It compresses the trachea of the abdominal cavity and reduces the volume of the tracheal cavity. As a result, the remaining six airways are opened. CO2 present in the trachea is forcefully expelled through these spiracles.