Wednesday, November 11, 2009

dissecting d worm

Our computer technician, Greg, is familiar with worms, the kind that replicates itself in computer programs. Never did he imagine that one day, in his stint as the Learning Resource Unit Officer in our school, he would be encountering (and in fact dissecting) another kind of worm, namely the lumbricus spp., humble earthworm of the kawayanan.

And why the earthworm? Well, it's because earthworms are true coelomates, and as such they have a body cavity that is lined with muscle on both the inside of the epidermal tissues and the outside of the endodermal tissues (gut). Coelomates have muscle lining their guts, thus peristalsis can occur independently of body movements.

We were studying the effects of different neurotransmitters, temperature and ions on gut activity. The wriggly-squiggly earthworms had to be immobilized first by soaking them in ethanol, to put them into a drunken stupor.

This experiment wouldn't work with the human ascaris because ascaris is a pseudocoelomate and as such does not have muscle tissue around its gut. (Not to mention that I think that would quite eewww, huh, dissecting an ascaris!)

L-R: My student (CL), our all-around-guy (Manong Nato) and our computer-guy (Greg)

gutting the gut

Lessons learned (among the many):

1. the bigger the earthworm, the easier the dissection, and the bigger the gut harvested (elementary)

2. the blunter the knife, the greater the number of earthworms that get macerated before we send for a new set of surgical blades (~_~)

3. dissecting earthworms is fun, especially for students who dream of becoming surgeons someday

4. the earthworms have to be duly anesthetized, before they will allow you to terminate their soil-y lives in the name of scientific advancement


Bone MD said...

hmmm..never practiced on worms before,nor did tried operating on them...i wonder if GA to RA???

ness said...

Hahaha, Doc Rems!

Our lesson was on GIT physiology as the worm gut has similarities to the human gut that's why we got their gut for experimentation, i.e. it's reaction to different chemical and physical environments.

And the anesthesia? Hehe. Ethanol to put them to drunken sleep. :-)

Ligaya said...

hala kaluoy sa earthworms doc...

ness said...


I hope walay taga PETA makabasa ani nga post... pero in fairness, naka-anesthesia sila, ha...