Sponsored Links

Poll: From the graph, curve B is

Be advised that this is a public poll: other users can see the choice(s) you selected.

Results 1 to 3 of 3

Thread: Step 1 HY 2

  1. #1
    Anonymous is offline Unregistered Guest
    Join Date
    Jan 2003
    Posts
    10,092
    Downloads
    0
    Uploads
    0
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Step 1 HY 2

    Advertisements





    Sorry the pic is not perfect, but it was the best I could find. The 2 curves should be equivalent except that one is further to the left than the other.

  2. #2
    Anonymous is offline Unregistered Guest
    Join Date
    Jan 2003
    Posts
    10,092
    Downloads
    0
    Uploads
    0
    Thanks
    0
    Thanked 0 Times in 0 Posts

    answer

    This is supposed to be something similar to a log dose curve seen in Pharm. I wish I could find a better pic like they have in Kaplan pharm, but if any of you have it or something similar, please look it up since it's an important concept.

    One axis should represent %response and the other represents log dose of drug. Antagonism will always displace to the right. There are 2 types of antagonism, competitive and non-competitive. In compet, parallel shift to the rt, maintenance of parallel slopes, and retention of same height of curve. In non-compet, shift to the right, loss of parallel slopes, and loss of curve height (dec efficacy). Potentiation will always give a parallel displacement to the left.

    From that info, we know that the curve from A to B is to the right, so it must be antagonism. We can also see that there is no loss of parallel slopes and no loss of curve height. So you should have included that this was competitive inhibition and the correct answer is a.

    You can take this a step further (like the USMLE exam will do, and use drug names instead. For example, A could be NE and B could be prazosin (tell me why). If B had lost it's height and slope, it could have been phenoxybenzanine (why?). A different scenerio could make B NE, and A Cocaine (why?).

    It's not just a matter of memorizing a graph, or memorizing which are compet vs non-com, etc. You need to be able to correlate the concepts into a multi-step question. But if you learn it correctly, you can answer any one of the many possible questions they might throw out at you by learning this concept.

  3. #3
    Anonymous is offline Unregistered Guest
    Join Date
    Jan 2003
    Posts
    10,092
    Downloads
    0
    Uploads
    0
    Thanks
    0
    Thanked 0 Times in 0 Posts

    my answer is A

    I am sure it is A.

Similar Threads

  1. Replies: 0
    Last Post: 05-15-2011, 10:06 PM
  2. FP physician USMLE Tutor- step 1 step 2 step 3- DC/MD?VA
    By eboni08 in forum USMLE Classifieds
    Replies: 1
    Last Post: 05-09-2011, 11:00 AM
  3. Usmle step 1, Step 2, Step 3 resources for sale
    By img123 in forum MUA Nevis Medical School Classifieds
    Replies: 3
    Last Post: 12-24-2010, 10:43 AM
  4. Failed step 1. Do I take step 2 ck first then go back to step 1?
    By luckyclover in forum USMLE Step 1 Exam Experiences
    Replies: 3
    Last Post: 03-20-2010, 10:56 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •