our physiology class today is the most disturbing class ever. today's topic was physiology of the excitable tissues. basically it centered on how electrical stimulation are able to produce response, easily recognizable are muscular contractions, secretions from glandular tissues and nerve impulses and reflexes.

so for today's topic, we did 2 experiments. they were called Galvani's experiment - she mentioned something about animal electricity but i can't quite remember what is the connection. oh, and the experiment was conducted on my table, so lyn and i were the direct spectators of the experiment.

The 1st Galvani's Experiment:

for the work it is necessary to have: a frog, a set of instruments for preparation, a galvanic pincer. Galvanic pincer is special pincers with copper and zinc legs (or another pair of different metals).

the succession of the work: distract the brain and spinal cord of the frog. cut the frog across in the region of upper thoracic vertebra. take off the skin from the hind extremities of the frog (holding the rest of the vertebral column by napkin). remove the rest of the viscera by the pincers. the preparation is placed on the glass plate. touch the plexus nervous by legs of galvanic pincers. the muscular contraction is observed.

from my observation: the instruction sounded easy wasn't it? but you wouldn't guess that the frog was going to be cut alive! probably for best results but..... ok, so the frog was alive, madam held both its hind legs with her bare right hand, open its mouth, and cut with a pair of scissors starting from the edge of the mouth all the way across its eyes to the other edge, revealing its spinal cord. the frog shrieked in pain.. that's the worst part...

and then she took a large and long needle then penetrated into its spinal cord to destroy it. while this happens, the muscles of the frog contracted, making it look as if it wanted to leap forward. then the skin was peeled from the frog, together with its organs leaving only it's vertebral column and hind legs.

after that the frog was hung on the galvanic pincers from its vagus nerve and the most curious thing happened (not exactly curious la because we studied the topic after all). the dead, skinless, organless body of the dead frog moved as if... i can't find the word, but it looked like the frog was trying to struggle free from the pincers.

the 2nd experiment used the same dead frog, to show how damaged tissues are able to produce electrical excitation (muscle contraction) when touched with the nerve (in this case, the femoral muscles and sciatic nerve - nerve that connects the spinal cord with the femur).

the image of the frog being cut alive across its mouth is very very higly disturbing. i don't even know how to get it off my system. i went to the lecture afterwards feeling very sick while the scene keep playing and replaying itself. when i got to my room, i tried sleeping but i dreamt about it. i woke up feeling so bad for the frog, and i wonder how on earth am i going to summon the courage to kill a different frog for our practical class next week - we're supposed to do it individually next week.

wallaweh.. die la..

it was like i had just been visited by a dementor!