Our Worm Lab

1. The pumping organs of the Worm are its hearts, or enlarged blood vessels

2. It first enters through the mouth, then the pharynx. It travels through the esophagus and into the crop and gizzard, and then through the intestine until the waste is excreted through the anus

3. The worms brain is made up of several ganglia, which is attaches to a long nerve that runs along the ventral side of its body, which connects it to the rest of the body. 

4. The parts of the worms body that are involved with the excretion of waste are the anus, and the nephridia, (which we could not find our lab sadly)

5. You can find out the worm's diet by looking at what can be found in it's digestive system. Soil for example will be found travelling through the digestive system, and if dissected, you can actually see what the worm ingests

6. The earthworm's setae are tiny bristle-like structures found on it's skin. These are very helpful in the movement of the worm, and they protect it by spiking out in soil to prevent any predators from grabbing it away from its habitat ( since my camera couldn't take a nice picture of the setae, i was able to find a species of worm with very visible setae)

7. The earthworm's crop stores the worm's food as it comes in through the esophagus, and the gizzard grinds it down until it is ready to be digested. This process of storing and grinding food makes the worm very well adapted to its environment ans explains why it can extract its food from the soil.

8. Past the 32nd segment of the worm,I would see the continuation of the digestive system, as well as more nephridia. I would also see the worm's food, mostly made up of detritus and soil.

9. Once earthworms begin to reproduce, they begin to attach themselves to one another and exchange their sperm, Since all earthworms are hermaphrodites, they collect the sperm and contain it in special sacs to be used once the eggs are mature. Once this happens, the clitellum begins to secrete a sticky substance in the form of a ring which is released with the eggs and sperm. This in turn creates a cocoon, which contains the now fertilized eggs.(The picture shows the seminal vesicles, which create the sperm needed for reproduction)

For our classes first major dissection, we were assigned to dissect an earthworm from the phylum Annelid. It was definitely one of the more exciting things we've done in our biology class, and one of the best dissections I've had yet, as odd as that sounds. Being a fairly visual learner, I found the dissection to be really informative, and quite the experience. We began with the pinning of the worm to the dissecting table, which brought more than a couple of squeals from my classmates, but it was easily done. The real work came when we had to make the major incisions. We cut down the length of the worm's dorsal skin, exposing all the organs and body parts that the earthworm had. Pinning the skin to the side, we started to view the various organs under the microscope, like the intestine and the worm's multiple hearts. Definitely the most disgusting part was when we viewed the bottom  half of the worm, which for us, contained the intestine, typhosole, and  the earthworm's diet of soil and decaying matter. The brown-black mess was eventually moved away as we wanted to view the worm's intestines in it's entirety. Once we were done, we spent a good amount of time cleaning up the various scalpels, pins, tweezers etc. and getting pieces of worm off of every surface that was visible. In the end, the dissection was a truly interesting experience, and i definitely helped us actually see what was inside of what we were learning about, not just be looking up diagrams of it in out textbooks and on the internet. This hands on experience makes what we're learning about that much more interesting and special.