Question

Give the location of hepatic caeca in the cockroach. What is their function?

Answer 1

Hint: Hepatic caecum is a part of the digestive system of cockroach. It has a function similar to the function of liver present vertebrates by secreting digestive juices.

Complete answer:
The hepatic caecum is located at the junction of the foregut and midgut of the cockroach and is made up of 6-8, thin, transparent blind tubules. These tubules are arranged in a rosette. It aids digestion by secreting digestive juices.

Additional information:
- The scientific name of cockroach is Periplaneta Americana, belongs to Kingdom Animalia and Phylum- Arthropoda, Class- Insecta.

- Cockroaches are omnipresent, usually found in damp and warm places like kitchen,manholes, etc. they are nocturnal in nature (active at night), curious in nature (fast runners). They have wings but rarely exhibit the ability to fly.

- Cockroaches are omnivores. Hence they can consume anything that is available to them. Digestive system of cockroaches consists of alimentary canal and salivary glands. The alimentary canal of cockroach has three segments- foregut (stomodaeum) , mid-gut (mesenteron) and hind-gut (proctodaeum).

- The mouth cavity is enclosed between anterior labrum, posterior labium and lateral mandibles and maxillae. The tongue or hypopharynx lies in the mouth cavity. Foregut consists of pharynx, oesophagus, crop and gizzard. The mixed food enters the mouth and reaches pharynx. Pharynx joins oesophagus. Oesophagus passes through the neck and opens in a crop which is a highly distensible pear shaped sac that stores food. From the crop, food enters the gizzard. Gizzard has a circle of six chitinous teeth that crush the food. This marks the end of foregut.

- The midgut is a coiled tubular structure. At the junction of foregut and midgut, there are 4-6 fingerlike structures called hepatic caeca. They are thin, transparent blind tubules arranged in rosette fashion in the anterior part of the stomach. Their function is to secrete digestive juices. The diagram below shows hepatic caeca.

Note: The word ‘hepatic’ refers to liver. Hence hepatic caecum performs functions similar to liver. Bile is a digestive juice released by the liver which emulsifies fat in higher organisms. The hepatic caeca release digestive juices necessary to break down complex food particles.