All About the Earthworm
Earthworm Dissection Pre-AP Biology Period 2 - Bowen Song
Earthworms are also hermaphrodites. They contain both the male and the female sex organs. They are present in most places where the soil is moist and undisturbed.
Mouth, segment, setae, sperm grooves, clitellum, anterior end, sperm duct openings
Brain, pharynx, esophagus, crop, gizzard, dorsal blood vessel, aortic arches
Earthworm Digestive System
Getting More in Depth
Parts of the earthworm digestive system: mouth, pharynx, esophagus, crop, gizzard, intestineFunctions: The gut of the earthworm is a straight tube which extends from the worm's mouth to its anus. It is differentiated into a buccal cavity (generally running through the first one or two segments of the earthworm), pharynx (running generally about four segments in length), esophagus, crop, gizzard (usually) and intestine.
Food enters through the mouth then moves into the esophagus, where calcium (from the blood and ingested from previous meals) is pumped in to maintain proper blood calcium levels in the blood and food pH. From there the food passes into the crop and gizzard. In the gizzard, strong muscular contractions grind the food with the help of mineral particles ingested along with the food. Once through the gizzard, food continues through the intestine for digestion. The intestine secretes pepsin to digest proteins. Instead of being coiled like a mammalian intestine, an earthworm's intestine increases surface area to increase nutrient absorption by having many folds running along its length.