Understanding Earthworm Anatomy: A Step-by-Step Guide to Dissecting and Examining

🪱 A worm is a type of invertebrate animal that includes earthworms, roundworms, and flatworms.

🔍 The anatomy of an earthworm consists of ringed segments called annuli, which are covered in tiny hairs called setae that help the worm move.

🌱 The worm's muscles extend and contract, using the setae as anchors, to move its body forward.

🔍 The worm's platelum secretes a cocoon for its eggs and helps with orientation.

🐛 The worm's anatomy is divided into anterior (head) and posterior (rear) ends, with a dorsal (back) and ventral (stomach) side.

🔪 The dissection process involves making an incision behind the clatalum and peeling away the flaps called septum to reveal the segments of the worm.

🔪 Cutting the worm reveals the cuticle, an outer protective layer.

🧠 The worm has a small brain with two lobes located near the head.

💡 The pharynx, located at the beginning of the digestive system, functions as a suction pump.

🐛 Worms have both male and female reproductive organs, with seminal vesicles producing sperm and seminal receptacles receiving sperm.

💓 Earthworms have five arch-shaped hearts called aortic arches that pump blood throughout their body.

🌬️ Worms breathe through their skin as they do not have lungs.

🌬️ Worms must stay moist in order to breathe, as air dissolves on the mucus of their skin.

💉 The aortic arches pump oxygenated blood throughout the worm's body.

🌽 The crop stores food until it can be moved to the gizzard, which has a thicker muscle lining to grind up the food.

🔄 The intestine absorbs nutrients from the food, and waste is expelled through the anus.

🪱 Earthworms are beneficial for plant growth as their droppings contain nitrogen and other nutrients.

💡 The intestine absorbs nutrients from food and distributes them through the worm's body via blood vessels.

🧠 The worm's ventral nerve cord, connected to the brain, acts as its spinal cord, allowing it to move and respond to stimuli.

🩸 The dorsal blood vessel carries blood to the front of the earthworm's body.

🧠 The ventral nerve cord and ventral blood vessel carry blood to the back of the earthworm's body.

💩 Cutting open the intestine reveals digested soil in the earthworm.