Organ and Organ Systems in Animals — Bio Zoology STD 11 — Question

The digestive system of cockroach consists of the alimentary canal and digestive glands. The alimentary canal is present in the body cavity and is divided into three regions: foregut, midgut and hindgut (Figure). The foregut includes pre-oral cavity, mouth, pharynx and oesophagus. This in turn opens into a sac like structure called the crop which is used for storing food.
The crop is followed by the gizzard or proventriculus which has an outer layer of thick circular muscles and thick inner cuticle forming six highly chitinous plates called ‘tecth’. gizzard helps in the grinding of the food particles. The midgut isa short and narrow tube behind the gizzard and is glandular in nature. At the junctional region of the gizzard are eight fingers like tubular blind processes called the hapatic caecae or enteric caecae.
The hindgut is marked by the presence of 100 – 150 yellow coloured thin filamentous maiphigian tubules which arc helpful in removal of the excretory products from the haemolymph. The hindgut is broader than the midgut and is differentiated into ileum. colon, and rectum.
The rectum opens out through the anus. Digestive glands of cockroach consist of the salivary glands. the glandular cells and hcpatic caccac. A pair of salivary glands is found on either side of the crop in the thorax. Thc.glandular cells of the midgut and hepatic or gastric caeeae produce digestive juices.