Digestive System of Earthworm MCQ - Practice Questions with Answers

 Alimentary Canal of Earthworm

• The alimentary canal is a straight tube that runs between the first segment to the last segment of the body of an earthworm
• The buccal cavity is situated in 1-3 segments
• It is followed by the muscular pharynx
• The pharynx is followed by an oesophagus in 5-7 segments
• It is followed by a muscular gizzard in 8-9 segments
• Gizzard helps in grinding the soil particles and decaying leaves
• Gizzard continues into stomach that extends from 9-14 segments
• Stomach contains calciferous glands that neutralise the humic acid present in humus
• The intestines are the major organs that begin from the 15th segment and continue until the last segment
• At segment 26, a pair of the intestinal caecae project from the intestine
• From segment 26 to 35, the intestine shows a characteristic feature called typhlosole
• Typhlosole are the internal medial folds of the dorsal wall
• Typhlosole increases the effective area of absorption in the intestine
• The alimentary canal opens into anus which is a round small aperture
• During digestion, the ingested soil is passed through the digestive track and is digested into small absorbable substances which are absorbed through the membranes of the intestine