Hey worm, watcha got inside ya?
Earthworm Dissection Lab
John Labador
04-09-14
Mitcham-PAPBio-2nd
Objective
- Describe the appearance of various organs found in the earthworm.
- Name the organs that make up various system in the earthworm.
Background Information
External Anatomy of the Earthworm
Internal Anatomy of the Earthworm
Earthworm Circulatory System
The earthworm like many more complex organisms has a closed circulatory system, meaning that its blood is confined to blood vessels and its blood is recirculated so it gets maximum use. An earthworm has neither lungs nor gills but uses its body's great surface area to absorb oxygen from the soil. The oxygen is taken in by the dorsal blood vessel and travels to the five aortic arches (hearts) by the esophogus where it is pumped to the lower, ventral blood vessel. The ventral blood vessel pumps the blood to all segments and organs in need of oxygen. In each segment, there is a small blood vessel that sends the blood from the ventral blood vessel back to the dorsal blood vessel, thus completing the loop (Musurca).
Other Informations
-There are approximately 2,700 kinds of earthworms
-The largest earthworm was found in South Africa and measured about 22ft
-Charles Darwin spent 39 years studying earthworms
-Worms are cold-blooded animals
Taxonomy
Cladogram
Evolution
Ecology
Habitat: soil
Predators: birds
Prey: dead organisms
Trophic Level: decomposers
Body Systems
2. Mouth - opening for food to enter
3. Pharynx - muscle to suck in food(dirt)
4. Intestine - digestion of food
5. Gizzard - grinding food
6. Anus - where wastes exit
7. Esophagus - tube where food is passed from mouth to crop
8. Pharyngeal Muscles - supports pharynx, sucks in food