oreomini.blogg.se

Those from the abdominal ganglia send nerves to the structures in the abdominal region. Nerves emanating from the thoracic ganglia innervate the musculature and structures of the thoracic region. The three thoracic ganglia and the last abdominal ganglion are large in size. The nerve cords are con­nected by nine ganglia, three thoracic and six abdominal. These are two solid nerves and run along the mid-ventral line of the thorax and abdomen. Pin down the head of the cockroach with ventral surface upward. Turn the crop as required and trace the ducts anteriorly running from the glands and the receptacles along the sides of the crop and then ventral to the oesophagus. Dissection of Salivary Apparatus :Ĭarefully remove all the tra­cheae and fat in the region where the salivary apparatus is lodged.

The ducts from the two glands unite and those from the receptacles also unite to form two common ducts, which again unite and give rise to an efferent salivary duct open­ing on the ventral side of the hypo-pharynx. The ducts of the glands and receptacles run forward by the sides of the crop. The glands and the receptacles lie on the dorsolateral aspects of the crop (Fig. The junction of the mid and hind gut is marked by 60 to 70 extremely fine, yellowish Malpighian tubules (The tubules are excretory in function.). 6.5).Ī short, vertically oriented tube opening into the oesophagus.Ī narrow tube, divisible into 3 zones – ileum, colon and rectum.

Ventral in position, located at the base of the buccal cavity.Īn ill-defined chamber, bounded anteriorly by epipharynx and labrum posteriorly by hypo-pharynx and labium later­ally by two mandibles (Fig. Prevent it from coming back to the original position by pushing down a pin in the wax between the gut and the specimen. Remove fat bodies and tracheae to expose internal organs.Ĭarefully uncoil the intestine and stretch the alimentary canal to one side (Fig. The thoracic and the abdominal cavity are exposed. Give a transverse incision along the anterior border of the first thoracic segment and carefully remove the terga. Proceed forward up to the anterior end of the thorax. Posteriorly the two inci­sions should meet at the hindmost end of the abdomen. Cut the lateral membrane (pleura) between the terga and sterna of the thorax and abdomen with a pair of fine scissors. Fix the specimen in a dorsal position on a dissecting tray with the help of pins passing through abdominal sterna and coxa of legs. 6.1) with your left hand and clip the wings.