Earthworm Dissection Flashcards

Earthworm Dissection Overview

• Studying and dissecting earthworms enhances understanding of various organisms.
• Earthworms belong to the phylum Annelida, characterized by segmented bodies.

Scientific Classification

• Earthworm's species name is Lubricous, indicating its specific classification within the Annelida phylum.

Anatomy and Physiology

• A coelom is defined as a fluid-filled cavity that provides space for the internal organs.
• Earthworms are hermaphrodites, possessing both male and female reproductive capabilities, producing sperm and eggs.

Feeding and Digestion

• Earthworms primarily consume organic particles in soil; they are classified as herbivores.
• Distinguishing between dorsal and ventral sides: dorsal is darker in coloration.
• Setae are bristle-like structures used for anchoring and movement through soil.

Reproductive Structures

• The clitellum is located at the anterior end and is essential during the mating process.
• Seminal vesicles are found above the esophagus and are where sperm maturation occurs.
• Seminal receptacles are situated in segments 9 and 10, playing a role in reproduction.

Excretion and Waste Management

• Excretory openings serve the purpose of expelling waste from the body.
• Digestion process: after the mouth, food travels to the pharynx, followed by the esophagus, which is obscured by the circulatory system.
• Food continues through the crop, gizzard, and intestine, with undigested particles eliminated via the anus.

Nervous and Circulatory Systems

• The ventral nerve cord is composed of a chain of ganglia and three pairs of nerves in each segment, coordinating movement and response.
• Nephridia function to collect and excrete waste, located on the left and right sides of the intestinal tract.

Circulatory Function

• The aortic arches mimic the function of the human heart by pumping blood through dorsal and ventral vessels.

Mating Process

• During mating, earthworms join at the clitellum to exchange sperm, later releasing an egg cocoon from which baby worms will emerge.