Earthworm dissection 001
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Transcript of Earthworm dissection 001
Earthworm DissectionLumbricus terrestrisKingdom: AnimaliaPhylum: Annelida
Students should Identify the following
• Segments• Septum• Setae• Pharynx• Esophagus• Crop• Gizzard• Intestine• Aortic Arches• Ventral Nerve Cord
• Dorsal Blood Vessel• Clittelum• Seminal Vesicles• Seminal Receptacles
Students should know the following terminology
• Invertebrate
• Castings
• Hermaphroditic
• Hydrostatic Skeleton
• Closed Circulatory System
Students will use the following tools for the earthworm dissection
• Scalpel
• Probes
• Dissecting Pins
• Rubber Padded Dissecting Tray
Scalpel
Dissecting Pins
Dissecting Pan
Before you start dissecting, find the following:
• Mouth
• Setae – the bristles used for locomotion. They are located by rubbing your fingers along the earthworm’s body. They are often times easier to feel than to see.
• Sperm Duct
• Clittelum
Mouth
Sperm Duct
Clittelum
Mouth
Pin your worm at the tip of the mouth and at its midpoint.
Start your incision 2 cm behind the clittelum.
Make sure not to cut too deeply.
Continue your cut to the mouth
Begin to separate the skin using pins
Pin the skin back as you go along the cut. Angle your pins outward so that are out of the way.
As you pin the skin back, take your probe and break the partitions between the segments. These are called Septum.
Pharynx
Aortic Arches – Earthworms have 5 pair of these simple hearts.
Aortic Arch
Seminal Vesicles
Seminal Receptacles
Crop
Gizzard
Dorsal Blood Vessel
Intestine
Ventral Nerve Cord
Ventral Nerve Cord
Brain
Nerve Cord and Brain
Brain