Cockroach dissection – Digestive system
October 29, 2019
These are a cockroach’s dissected mouthparts.
Their mouth organs, the maxilla, mandibles, and labium, are used to taste food and handle
food pieces. Cockroaches use their mandibles, or jaws,
to bite and chew their food. From the mouth organs, the food passes into
the foregut, or esophagus. The foregut opens into a crop, where undigested
food is temporarily stored. From the crop, the food enters the gizzard.
The gizzard is a muscular stomach with sharp teeth-like structures that grinds the food
into smaller pieces. The gastric sacks contain bacteria that the
cockroach uses to digest its food. The Malpighian tubules are the main organs
of the cockroach’s excretory system. The Malpighian tubules remove wastes from
the hemolymph, in the body cavity surrounding the cockroach’s organs and tissues.
These organs also regulate the balance of water and salts in the cockroach’s body.
The contents of the Malpighian tubules are emptied into the midgut, which is also called
the ileum. Most of the absorption of the food’s nutrients
takes place in the midgut, or ileum. In the hindgut, or colon, water, salts, and
nutrients are reabsorbed from the feces and urine.
The remaining wastes leave the body through the rectum, which is also part of the excretory