Earthworm Anatomy and Physiology Quiz

Earthworm Anatomy and Physiology

• The prostomium is a flap of tissue that covers the earthworm's mouth.
• Sperm received during mating enters the worm through the seminal receptacle.
• Earthworms breathe through their skin (epidermis).
• The clitellum secretes mucus during mating.

Reproductive Structures

• The cocoon is a capsule that contains fertilized eggs.
• Sperm produced by the testes is stored in seminal vesicles.
• Ovaries are responsible for egg production.
• After mating, the seminal receptacle bulges with sperm.

Digestion and Excretion

• Castings are undigested food excreted from the worm's anus.
• The gizzard is the main organ for chemical digestion and grinding food.
• The typhlosole increases the intestinal surface area for enhanced digestion.
• Food is neutralized with calcium carbonate in the esophagus.
• Nephridia are responsible for removing nitrogenous waste.

Circulatory System

• The dorsal blood vessel transports blood toward the anterior end of the worm.
• Blood is transported through the ventral blood vessel.
• Peristaltic waves move the blood within the dorsal blood vessel.

Locomotion and Muscle Function

• Setae help earthworms anchor themselves for locomotion.
• Longitudinal muscles cause the worm to shorten and thicken.
• Circular muscles contracting make the worm thinner and longer.

Nervous System

• The nerve cord is located along the ventral side of the earthworm.
• The brain is situated above the pharynx.

Other Structures

• The crop serves as a temporary storage place for food.
• The pharynx creates a vacuum to suck soil into the worm's mouth.
• Glands in the intestine secrete enzymes that aid in food digestion.