Earthworm Intensive Acupuncture

Hannah Reeves 4/7/14 Vu-PAP Bio-4


To observe the internal and external anatomy of an earthworm

Earthworm Facts

Scientific Name: Lumbricus terrestris

  • Earthworms live underground where they can find food, moisture, oxygen, and a favorable temperature.
  • Natural predators of the earthworm include birds, rats, and toads.
  • Earthworms are herbivores.
  • Earthworms loosen, aerate, and fertilize the soil as they burrow. These burrows provide passageways for plant roots and improve drainage.
  • Earthworms have the ability to replicate and repair damaged segments of of it's body.
  • An earthworm's anterior end can sense light despite its lack of eyes.

Earthworm Digestive System

General: An earthworm's digestive tract is really just a tube that runs from the mouth cavity to the anus. This is referred to as a complete digestive system. The digestive system provides energy for the entire body by removing glucose and other helpful nutrients from it's food. The digestive system works closely with the circulatory system because it is the circulatory system that transports the nutrients after the digestive system extracts them.

Mouth Cavity: This is simply the mouth of an earthworm. It begins the digestive system by bringing food into the worm. It is surrounded by strong lips that act like a hand. These lips also help to break up food.

Pharynx: This organ follows the mouth cavity on the digestive tract. It envelops the eaten food and soil in a mucus and enzymes that help pass it through the esophagus.

Esophagus: This is a slender organ and is hidden behind other body systems when the interior is viewed from the dorsal side. It also adds calcium carbonate to the eaten to neutralize the acids that are formed when the food matter decays.

Crop: This is a thin-walled sack that holds the eaten between the esophagus and the gizzard. The eaten here is also mixed during its temporary stay.

Gizzard: This is a thick-walled organ that grinds the eaten into small pieces so that the nutrients can better be absorbed. It also adds enzymes which help break down the organic material. By the time the eaten leaves it is no more than a thick paste.

Intestine: This organ is the one that actually absorbs the nutrients from the food and for that reason is very long so it can be more thorough. Tiny little blood vessels line the intestine and help absorb some of the vitamins, minerals, carbohydrates, and proteins released from the organic matter.

Anus: This is what expels any left over food and soil after the intestine absorbs all that it will from the eaten. These deposited leftovers are referred to as a worm cast.

Earthworm Ecology (click)

Check out where they live and their ecological function

Earthworm Anatomy