You dissect a frog muscle with its motor nerve intact and place it in a chamber filled with Ringer?

Question

You dissect a frog muscle with its motor nerve intact and place it in a chamber filled with Ringer, a solution which approximates the normal ionic composition of extracellular fluid. You position two stimulating electrodes on the preparation, one on the nerve and the other directly on the muscle. Stimulating via either electrode causes muscle contractions. What would happen after you applied a toxin that blocked voltage-gated Ca2+ channels?
a. The muscle would contract when stimulated via the nerve, but not when stimulated directly.
b. The muscle would continue to contract normally when stimulated at either location.
c. The muscle would not contract when stimulated at either location.
d. The muscle would contract when stimulated directly, but not via the nerve.

Answer 1

C

Calcium is vital to enable the muscle contraction.

Answer 2

I think it would also be C, because the electrical impulse would activate the voltage gated Ca2+ channels. This is the first step in the process of the contraction, so if that early step is blocked, I would believe that the muscle would not contract when stimulated at either location.

Answer 3

I wouldn't know: I paid someone $20 to dissect my frog in biology class. I could't do it to that poor bas*tard.

So much for a medical career as a surgeon.......

Answer 4

it is A