Respiratory System and Excretory System of Cockroach - Practice Questions & MCQ

Respiratory System and Excretory System of Cockroach

Respiratory system

• Respiratory system of cockroach includes a system of tubes or tracheae.
• These tracheae receives air through 10 pairs of small openings called spiracles.
• The spiracles are located on the lateral sides of the body of insect.
• Each trachea divides into thin branches called tracheoles which carry oxygen from the air to all the parts of the body.
• The openings of the spiracles are regulated by the sphincters. 
• The exchange of gases takes place at the tracheoles by diffusion
• Out of the ten, the 1st and 3rd pair of spiracles always remain open, while the rest of them open only during inspiration. 
• The process of respiration is associated with the contraction and relaxation of abdominal muscles called tergo-sternal muscle.
   

Excretory system

• Cockroach is uricotelic i.e. it excretes uric acid.
• The process of excretion occurs through Malpighian tubules, fat body, nephrocytes and uricose glands or mushroom glands.
• At the junction of midgut and hindgut, a ring of 100-150 yellow coloured thin filamentous Malpighian tubules are present.
• Each Malpighian tubule is lined by glandular and ciliated cells. 
• These absorb waste and convert it into uric acid which is excreted out through the hindgut.