1. Hepatic caeca
2. Malpighian tubules
For functions:
Hepatic caeca: These are thin, transparent, short, blind (closed) and hollow tubules.
Function: They secrete digestive enzymes.
For functions:
1. Malpighian tubules are the main excretory organs of cockroach.
2. They are thin, yellow coloured, ectodermal thread-like structures that lie in the
3. These tubules are 150 in number. Malpighian tubules are attached to the alimentary canal between the midgut and hindgut.
4. Each Malpighian tubule is lined with a single layer of glandular epithelial cells having microvilli. The distal portion of Malpighian tubule is secretory and the proximal part is absorptive in function.
5. They extract water and nitrogenous wastes from the haemocoel and convert them into uric acid and pass them into ileum. As the cockroach excretes uric acid, it is said to be uricotelic.
6. Also, fat bodies, nephrocytes and uricose glands (only in males) help in excretion.
7. In cockroach, nephrocytes (urate cells) associated with fat bodies and cuticle are also believed to be excretory in function. The nephrocytes are cells present along with the fat bodies or present along the heart and store nitrogenous wastes.
8. The excretory products later are removed in the haemocoel. Some nitrogenous wastes are deposited on the cuticle and eliminated during moulting.
