Explain the digestive system of Cockroach with the help of a labelled sketch.

Cockroaches have an advanced and well differentiated digestive system which has all the necessary primary and accessory organs. Cockroaches are omnivorous in nature. Their alimentary canal consists of three parts:

(A) Foregut

(B) Midgut

(C) Hindgut

These can be further described as:

(A) Foregut: The foregut consists of the mouth in cockroaches. The buccal cavity is located after the mouth. It consists of the tongue and hypopharynx. After the buccal cavity, the pharynx is located which is further followed by oesophagus.

The oesophagus is a narrow tube-like structure which leads to an organ known as crop.

The crop is a large sac-like structure which is used for the storage of food materials ingested by the cockroach.

(B) Midgut: Midgut is a narrow and short tube like structure. It has an organ known as gizzard which grinds the food into simpler components. The gizzard has hepatic caeca which produces digestive enzymes.

(C) Hindgut: The hindgut is further divided into three major parts: Ileum, Colon, and Rectum. The Malpighian tubules are also present in the hindgut. Malpighian tubules help in the elimination of the nitrogenous wastes and convert them to uric acid. It also maintains the ion balance in the cockroaches. The anus is the last part of the digestive system of the cockroach.