Earthworm DIEsection Lab

I consider myself as a "man". However, when we were dissecting earthworms on this Friday, I was hesitant to state myself that. Before I get into details about the dissection of the worm, I'd like to say that this lab was simply amazing. Through this lab, I could vividly see, almost touch the worm parts and their organs, and this helped me understand the whole Phylum Annelida to a whole new level. For example, now I have a clear idea what a true coelom is. Before, I had to just had to nod my head with the vague description given: "body cavity which allow them to have true organ systems and muscular layers". Now I know that earthworms have true coelom, just like humans. Another great thing about this lab was, I got to see not only the outside parts of the worm, but see all the inside and guts of the worms. The digestive tube of the worm looked like a long trail of black ink. The digestive system of the worm was interesting to look at because not only the tube connects the mouth and the anus, it also was very dirt-like. The hearts, however, looked completely different and, out of the ordinary. In fact, there were five of them. The heart, otherwise known as the aortic arches, pump blood through the worm's body.

In retrospect, I understand why this lab was done - to observe how an earthworm's structures of earthworm anatomy. At that time, I was busy freaking out and having a great time by observing a worm's internal organs. In the lab, I followed the instructions on the hand-out carefully, and proceeded to dissect the whole worm. However, I was pretty messy with the surgery; I am pretty sure I squished an organ here and there. Overall, I think this lab has really stepped up my knowledge in the Phylum Annelida. I'd give it 10/10.

Responses

1. The name of the pumping organs of an earthworm is
called the "Aortic Arches" or, the hearts

2. The food passes through the Mouth, pharynx, esophagus,
crop, gizzard, and intestine. (in order)

3. The parts that serve as an earthworm's brain are the ventral nerve cord,
because its brain and the cords are attached together, and travels
throughout the length of the worm.

4. The parts of the worm's body that were included in the
excretory system, that I got to observe was the Nephridia
and the anus (not labelled on photo). The anus is located at the opposite end of the head of the worm. 

5. One can conclude that a particular earthworm eats soil
by observing the black intestine of the worm.

CREDIT: http://www.angelfire.com/ny4/sci7/Setae.jpg
6. An earthworm's seatae make it well adapted to its habitat by  helping
earthworms anchor into the soil while burrowing, digging, and moving
around in the dirt. Without this adaptation, the worms will have much
harder time trying to squiggle. (LOCOMOTION)

CREDIT: #2 OF MY QUESTION
7. The earthworm's digestive system is adapted for extracting relatively small
amounts of food from large amounts of ingested soil by digesting the dirt
through its long intestine. Also, the gizzard breaks the food down, completing
an unending "digestive cycle"

8. The reason that our dissection did not go beyond segment 32 is because
it is disgusting, and all the juicy stuff is located at the anterior part of the worm.
As we dissect down, we will possibly able to spot the liquid substances that 
the worm ate.

Earthworms fertilize by sexually mating. During this process,  two
worms line up opposite to one another, and exchange sperm. The Citellium
forms a slime tube. As the worm moves through it, it will pick up female pore,
eggs. The tube will continue to move down the earthworm and pass over
the male pore called the spermatheca which has the stored sperm
called the spermatozoa. Finally, the slime tube will close out, and forms an
egg cocoon that will be placed in the soil.