Diagram of alimentary and digestive glands in cockroach.

What are functions of these glands.

• Digestive system of cockroach is of tubular type. It means its in the form of tube. Mouth is for ingestion and anus is for egestion.

• It can be divided in to 3 parts.• 1/foregut• 2/ mid gut• 3/hind gut

Forgut

• It is composed of 4 parts.• 1/mouth cavity• 2/ pharynx• 3/ crop• 4/ gizzard

Salivary Glands

• One pair is located in thorax region.• These glands secrete saliva which gets poured

in to mouth cavity.

Midgut

• It is short narrow tube.• This tube is called mesenteron stomach.• Hepatic caecae open in to front( anterior) end

of mid gut.• Hepatic caecae are short finger like hollow

tubes.

Hind gut

• It is a long coiled tube.• Last part of tube Is thick walled chamber ,

called RECTUM.• Rectum opens to exterior(outside) through

anus.• Anus also called cloacal aperture.

What happens in the mouth

• Cockroach eats all kinds of food.• It cuts food in to small pieces with the help of

mandible ( cockroach jaw bone).• Food gets mixed up with saliva in mouth.• Saliva has digestive enzymes.• Digestive enzymes hydrolyse the starchy

matter.

Crop• Partly digested food is stored in the crop.• Food leaves the crop chunk by chunk

Gizzard

• Partly digested food gets grounded in the gizzard.

• Then food goes to midgut

Role of hepatic caecae

• They secrete enzymes

In the mid gut

• Secretion of hepatic caecae and mid gut digest food in midgutcompletely.

Rectum

• It’s a place of temporary storage for indigestable food.

Anus

• Faecal matter is expelled through an opening called anus

Tubular digestive system

• It is more advanced than sac like digestive system.

• In this system there are specialised organs or partitions.

• That is why digestion and absorption is efficient.