Welcome Guest Search | Active Topics |

Tag as favorite
AAMC Biology Question pack 1 question
Korolos_5348
#1 Posted : Wednesday, July 15, 2020 9:59:59 PM
Rank: Member

Groups: Registered
Joined: 3/27/2020
Posts: 11

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hello,

I just came across a question I found confusing and I was wondering if someone could confirm if my understanding is correct. The stem is

"Which of the following changes would NOT interfere with the repeated transmission of an impulse at the vertebrate neuromuscular junction?"

The answer choices are

A. Addition of a cholinesterase blocker
B. Addition of a toxin that blocks the release of acetylcholine
C. An increase in acetylcholine receptor sites on the motor end plate
D. Addition of a substance that binds to acetylcholine receptor sites

I narrowed the answer choices to A and C and eventually chose A but I wasn't able to decide which one was correct. The correct answer was C. Is option A wrong because blocking cholinesterase would cause buildup of ACh which would eventually cause down-regulation of ACh receptors which would decrease neural transmission?

Thank you in advance


INSTR_Shinthujah_68
#2 Posted : Wednesday, July 15, 2020 10:29:06 PM
Rank: Member

Groups:
Joined: 6/8/2020
Posts: 22

Thanks: 0 times
Was thanked: 0 time(s) in 0 post(s)
Hi,

Yes you're correct in the sense that by blocking cholinesterase you will get a buildup of AcH in the junction. With the continued presence of AcH and with it binding to its receptor, the contraction elicited from the first impulse will not end leading to uncontrollable muscle movement. It also means that it WOULD interfere in the repeated transmission of impulses at the NMJ, so A is wrong.

I hope this helps!

-Shin
Users browsing this topic
Guest
Tag as favorite
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.

Clean Slate theme by Jaben Cargman (Tiny Gecko)
Powered by YAF | YAF © 2003-2009, Yet Another Forum.NET
This page was generated in 0.086 seconds.