Tuesday, December 27, 2016
Earthworm digestive system
In this video, I would like to talk about the digestive system of an earthworm.
An earthworm may seem like a simple organism but it has a sophisticated digestive system.
Earthworms like to eat dirt. They begin with their mouth where they swallow their food. The mouth is covered with a flap that can act as a wedge that helps the earthworm get through the soil called a prostomium.
It can be difficult to identify the head and tail of an earthworm. The easiest way is to remember the mouth is always closest to the clitellum which is a cocoon for the developing young of the earthworm.
From the mouth the food travels to the pharynx, at the pharynx, the food is lubricated by mucus secretion at this point the food which is basically dirt becomes very slimy and slick and passed on to the esophagus where the food is mixed with calcium carbonate.
From the esophagus, the food travels to the crop. The crop is a storage area and the food gets mixed with together. From the crop, the food moves into the gizzard.
Earthworms do not have teeth to grind their food but the muscles of the gizzard. Sometimes in the dirt there are small rocks and sand grains that help to grind up the food and some chemical digestion occurs in the gizzard.
From the gizzard, the food is now an in a paste. Next, it moves to the intestine. The bulk of the earthworm's body is made of the intestine, and the food passes through the earthworm and the intestine. While it passes friendly bacteria begin to break down the food so that the blood vessels that line the intestine can absorb the nutrients and carry the nutrients to other parts of the worm.
Finally, all this food with the waste removed is secreted out of the anus which is the end of the intestine. The waste of an earthworm is called casts. Farmers and other people who like to grow stuff love earthworms because they enrich the soil., and makes growing plants easier.
The digestive system of an earthworm. Thanks for watching and MooMooMath uploads a new Math or Science video every day.