Earthworm Internal Anatomy Dissection What you need per

Earthworm Internal Anatomy Dissection

What you need per group n n 1) 2) Dissecting tray (1 per table) Probe (1 per table) Earthworm Internal Dissection Lab Worksheet (1 per student) Moisten Paper towel & lay flat onto the dissecting tray Place Earthworm on paper towel CLASSWORK: LABEL CIRCULATORY & DIGESTIVE SYST & Describe the Functions of the Digestive System (STAMP NEEDED)

Lab Members Duties Dissection Team per Table n n 1 Surgeon per Earthworm 1 Reader per Earthworm 1 Recorder CLEAN UP DUTIES: EVERYONE HELPS OUT.

What to do when cleaning up? n n n Wrap worm in the paper towel Toss paper towel in trash Return probes, pins, and scissor back to the cart

Prepping Earthworm n n n Lay worm dorsal side up Pin down the mouth & tail end of the worm to the tray Always keep worm moist (to prevent drying) with a small drops of water Pin

Dissecting 101 n n n Cut worm from the end of the Clitellum towards the mouth Using a dissecting scissors to cut through skin Cut to the right of the dorsal blood vessel (dark mid line) Direction of Dissecting

Male Reproductive System (Seminal Vesicles) n n n Identify and take a picture of the Seminal Vesicles. Consist of 3 white lobes on both sides Function: Sperm Storage

Digestive System (The Pharynx) n n Using a probe, locate the pharynx Take picture

Digestive System (The Esophagus) n n n Using forceps, carefully remove the seminal vesicles, exposing the long tube underneath Using a probe, locate the esophagus Take a picture

Digestive System (The Crop) n n Using the probe located the crop Take a picture Use a probe and gently press against the crop, how does it feel? Answer for 3 a. Function: Stores food

Digestive System (The Gizzard) n n Using the probe located the gizzard Take a picture Use a probe and gently press against the gizzard, how does it feel compared to the crop? Answer for 3 a. Function: Grinds up food

Digestive System (The Intestine) n n Using the probe located the intestine Take a picture 80% of the worm’s body consist of the intestine Function: Absorbs nutrients from food

Circulatory System (5 -ringed Heart) n n n Use a probe to locate the 5 -ringed Heart (Black thin rings around from the esophagus) Take a picture Function: Pump Blood to blood vessels

Circulatory System (Dorsal Blood Vessel) n n Use probe to locate the dorsal blood vessel (black mid line on Dorsal Side) Take a picture

Circulatory System (Ventral Blood Vessel) n n Use forceps to lift the intestine to expose the ventral blood vessel (thin black mid line) Take a picture

Nervous System (Nerve Cord) n n Use forceps to lift the intestine to expose the nerve cord (thin white mid line, next to ventral blood vessel) Take a picture

CLASSWORK n n n Answer Analysis & Conclusion Qs (1 -4) Label & Color the Earthworm Diagram Print Pictures and Label the following 1. Seminal Vesicles 6. Intestine 2. Pharynx 7. Five-ringed heart 3. Esophagus 8. Dorsal Vessel 4. Crop 9. Ventral Vessel 5. Gizzard 10. Nerve Cord