Internal anatomy of an earthworm (cross section): small, long, cylindrical animal without legs or hard body parts.
Epidermis: outer part of the skin.
Dorsal blood vessel: blood vessel situated in the rear part of an earthworm.
Longitudinal muscle: muscular tissue that runs lengthwise on an earthworm.
Circular muscle: circular muscular tissue of an earthworm.
Intestine: digestive tract of an earthworm.
Ventral blood vessel: blood vessel situated in the front part of an earthworm.
Body cavity: more or less empty part of an earthworm.
Seta: fin thread secreted by an earthworm.
Ventral nervous cord: set of nerves in the abdomen of an earthworm.
Nephridium: organ of an earthworm that performs the functions of kidneys.