About Digestive system of cockroach
Answers
Explanation:
The digestive system consists of the alimentary canal and digestive glands. The alimentary canal of cockroach is divided into foregut, midgut, and hindgut.
The mouth opens into a short tubular pharynx, leading to a narrow tubular passage, the oesophagus. The oesophagus opens into a sac-like - crop, which is used for storing food. The crop is followed by a gizzard or proventriculus.
Gizzard consists of six - chitinous plates called teeth which help in grinding food. The entire foregut is lined by the cuticle.
A ring of six - eight blind tubular structures called hepatic or gastric caeca is present at the junction of foregut and midgut which secrete digestive juice.
At the junction of midgut and hindgut is present another ring of yellow coloured thin filamentous malpighian tubules which help in removal of excretory products from haemolymph.
The hindgut is broader than midgut and is differentiated into the ileum, colon, and rectum.
The rectum opens out through the anus.
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→ Alimentary canal has 3 parts:- Foregut, mid gut & hindgut.
→ Foregut:- It is lined by cuticle. It includes Mouth-pharynx oesophagus crop - gizzard.
→ Gizzard helps in grinding the food.
→ It has an outer layer of thick circular muscles and thick inner cuticle forming 6 chitinous plates.
→ Mid gut:- It is not lined by cuticle. 6-8 tubules are seen at the junction of foregut and mid gut.
→ They secrete digestive juice.
→ At the junction of mid gut and hindgut there is 100-150 yellow coloured thin filamentous Malpighian tubules which are excretory in function.
→ Hindgut:- It is broader than mid gut and lined internally by cuticle.
→ Hindgut includes ileum, colon & rectum. Rectum opens out through anus.