Alimentary Canal of
cockroach :
The alimentary canal is
in the form of tube present in the body
cavity
Alimentary canal of
cockroach is divided into three regions
are as follows:
1. Fore gut
2. Mid gut
3. Hind gut.
Fore gut- it is also
called as stomodaeum. It consists of mouth, pharynx, oesophagus, crop chamber
and gizzard.
The mouth is present to
the anterior end which opens into a short tubular pharynx, leading to a narrow
tube called oesophagus.
The oesophagus leads into large sac like
structure called crop. Crop is used for storing of food.
The crop is followed by
gizzard. It has rounded highly muscular part. The lumen of crop chamber shows
presence of Six chitinous teeth.
Gizzard helps in grinding the food particles.
At the junction of fore
gut and mid-gut there is presence of 6-8 blind tubules called hepatic or
gastric caecae which secrete digestive juice.
Mid-gut
–It is in the form of elongated and coiled tube. The digestion and absorption of food takes
place in this part.
Hind gut
– it is also called as proctodium. It is coiled and pigmented part of
alimentary canal. The hindgut consist of
ileum, colon and rectum.
At the junction of
mid-gut and hind-gut there is presence of ring of 100-150 yellow coloured
thin filamentous Malpighian tubules. The malpighian tubules are the most important
part of excretory system, help in removal of nitrogenous waste from the
haemo-lymph.
The rectum is most
posterior part of alimentary canal. The undigested food is temporarily stored into the rectum.
