WORM DISCUSSION PROJECT

BODY SYSTEMS

Respiratory System
They breathe by diffusing air directly through their skin. Their skin must stay moist for the gas diffusion to work properly, which is why they stick to damp soil and don't usually venture out into the hot sunshine.

Circulatory System
An earthworm has a closed circulatory system that uses vessels to send blood through its body. Smaller capillaries help the blood absorb nutrients and oxygen or carbon dioxide and carry them to the proper areas of his body.

Muscular System
earthworms have a powerful muscular system. Circular muscles squeeze inward while stretching out to the sides, going in waves down the earthworm's body. This pushes his body forward.

Digestive System
Digestion takes place in nearly a straight line down the earthworm's body. When worm swallows it until it passes through the gizzard, which uses tiny stones to grind up the food and pass it onto the intestines. In the intestines, the nutritious pieces are absorbed and the waste passed to the excretory system.

Excretory System
Part of an earthworm's excretory system is directly connected to his digestive system, as the intestines pass waste through the anus and out of the worm. This poop is called castings, and it serves as a type of plant fertilizer.

Nervous System
Earthworms have nerve clusters called ganglia that are connected to a nerve cord that run down the worm's length. The ganglia transmit electrical signals from the nerve cord to various other systems, such as telling the muscles to contract or the gizzard to start grinding food.

Reproductive System
An earthworms needs to mate with another worm to produce eggs, but they don't have to look for a specific gender. Most earthworms are hermaphrodites, which means they carry both male and female reproductive organs. To mate, the earthworms basically exchange sperm. Then, each earthworm lays eggs fertilized by the other's sperm.

FACTS ABOUT EARTHWORM

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DISSECTION EXPERTISE

• lay the worm on its __ side
• Pin down ends with needle
• cut down center of worm with scalpel gently
• Use twizzers to open up worm and gently cut at the small muscles
• Use more pins to pin back skin. Continue process all the way down