Скачать или смотреть Digestive system of cockroach

Join this channel to get access to perks:
   / @mageshbiology  
Digestive System
The digestive system of the cockroach consists of an alimentary canal and digestive glands.

Alimentary Canal

The alimentary canal is present in the body cavity and is divided into three main regions:

foregut, midgut, and hindgut.

1. Foregut:

○ This region includes the pre-oral cavity, mouth, pharynx, and oesophagus.

○ The oesophagus opens into a sac-like structure called the crop, which is used for storing food.

○ The crop is followed by the gizzard or proventriculus.

■ The gizzard has an outer layer of thick circular muscles.

■ It has a thick inner cuticle forming six highly chitinous plates called "teeth".

■ The gizzard helps in the grinding of food particles.

2. Midgut (Mesenteron):

○ The midgut is a short and narrow tube located behind the gizzard.

○ It is glandular in nature.

○ At the junctional region of the gizzard and midgut, there are eight finger-like tubular blind processes called the hepatic caecae or enteric caecae. These caecae produce digestive juices.

3. Hindgut:

○ The hindgut is marked by the presence of 100-150 thin filamentous
yellow-colored Malpighian tubules. These tubules are excretory in function,
helping in the removal of excretory products from the haemolymph. (As discussed in the previous response on the Excretory System).

○ The hindgut is broader than the midgut.

○ It is differentiated into three parts: ileum, colon, and rectum.

○ The rectum opens out through the anus.

Digestive Glands

The digestive glands of the cockroach consist of:

1. Salivary glands: A pair of salivary glands is found on either side of the crop in the thorax.

2. Glandular cells: These are located in the midgut and hepatic or gastric caecae.

These glands (salivary glands, and the glandular cells of midgut and hepatic caecae) collectively produce digestive juices that aid in the digestion of food.