Question

Explain the respiratory system of cockroaches.

Answer 1

Hint: It is a terrestrial organism found in damp areas. And it is an omnivorous insect feeding on food grains, cereals, and other animals. They can consume any organic matter. The trachea plays a vital role in the transport of respiratory gases hence the respiratory system.

Complete answer
-In cockroach, the respiratory system is a network of trachea known as the tracheal system.
-They respire through the small openings called spiracles. These openings are regulated by muscular sphincters.
-They breathe in oxygen-rich air through the spiracles which open into the tracheal tubes. The tracheal tubes are the network of air tubes meant for the smooth exchange of gas. These are found only in insects.
-The air at that point surges towards the tracheal tubes and afterward diffuses into the diverse body tissues and cells.
-The trachea is then subdivided into a thinner tube called tracheoles.
-Tracheoles contain a network of fluids that flow throughout the body of the insects.
-The air rich in carbon-dioxide surges towards the tracheal tubes and is, at last, breathed out through the spiracles.
Mechanism of respiration :
•In cockroach respiration includes two phases
(i)Inspiration
(ii)Expiration
Inspiration:
• Intake of atmospheric air or oxygen into the tracheal system is called inspiration. Inspiration is a passive process in the cockroach.
• At whatever point tergo sternal muscles relax, the space present in the body cavity increments and pressure diminishes.
• Thoracic spiracles are kept open and the Abdominal spiracles are kept shut.
• Later, that air is carried towards tracheoles and diffuses into tissues through the tracheal fluid.
• Due to metabolism carbon dioxide produced in tissues.
Expiration :
•Elimination of carbon dioxide is known as expiration.
•Whenever tergo sternal muscles contract, the space present in the body hole diminishes, and pressure increases.
•Thoracic spiracles are shut and stomach spiracles are kept open.
•In cockroaches a major amount of carbon dioxide is sent out by diffusion method through the cuticle.
•In cockroaches respiratory movements are controlled and coordinated by the nervous system.
•Expiration is an active process.

Note:
-Cockroach, Grasshoppers, and Beetles show the marvel of irregular ventilation.
-In this, the exchange of gases is interrupted by extended periods during which spiracles arc closed.
-Opening and closing of spiracles is influenced by carbon dioxide tension in the hemolymph and oxygen tension in the tracheae.