Question

Explain the respiratory system of cockroaches?

Answer 1

Hint: The respiratory system is the network of organs and tissues that helps an organism breathe. It includes the airway passage, the lungs, and the blood vessels.

Complete step by step answer:
A cockroach has small openings on the side of its body. These openings are called spiracles. Insects have a network of tracheae (air tubes) for gas exchange. Oxygen-rich air rushes through the spiracles into the tracheal tubes. It then diffuses into the body and reaches every cell of the body. Simultaneously, carbon dioxide from the cells goes into the tracheal tubes and moves out through spiracles. These air tubes or tracheae are unique only to insects.
- It breathes in oxygen-rich air through the spiracles which open into the tracheal tubes. These tubes are found only in insects.
- The air moves towards the tracheal tubes and afterward diffuses into the diverse body tissues and cells.
- The trachea is subdivided into a thin tube called tracheoles.
- Tracheoles have specific fluids that flow throughout the body of the insects.


Mechanism of respiration :
1) In cockroaches respiration includes two phases
(i)Inspiration
(ii)Expiration

Inspiration:-
1) Intake of atmospheric air or oxygen into the tracheal system is known as inspiration. It is a passive process in cockroaches.
2) During inspiration, the thoracic spiracles are kept open while the Abdominal spiracles are kept shut.
3) Later, that air reaches the tracheoles and diffuses into tissues through the tracheal fluid.

Expiration:-
1) The process of breathing out of carbon dioxide is known as expiration.
2) During expiration, the thoracic spiracles are shut and stomach spiracles are kept open.
3) In cockroaches, a major amount of carbon dioxide is expired out by diffusion method through the cuticle.
4) In cockroaches respiratory movements are controlled and coordinated by the nervous system.
5) Expiration is an active process.

Note: Insects that are diapausing or non-mobile have low metabolic rates and need to take in lower oxygen. Insects are the only organisms that exchange oxygen and carbon dioxide through spiracles.
Cockroaches, Grasshoppers, and Beetles show marvels of irregular ventilation.
- In this, the exchange of gases is interrupted by extended periods during which spiracles were closed.
- Opening and closing of spiracles are influenced by carbon dioxide tension in the hemolymph and oxygen tension in the tracheae.