Questions in CNS pharmacology - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
Home
USMLE Articles
USMLE News
USMLE Polls
USMLE Books
USMLE Apps
Go Back   USMLE Forums > USMLE Step 1 Forum

USMLE Step 1 Forum USMLE Step 1 Discussion Forum: Let's talk about anything related to USMLE Step 1 exam


Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 11-08-2015
USMLE Forums Scout
 
Steps History: Not yet
Posts: 33
Threads: 20
Thanked 3 Times in 2 Posts
Reputation: 13
Send a message via Skype™ to Albatoul Khaled
Default Questions in CNS pharmacology

1- In First aid 2014 page 495 in mechanism of local anesthetic, it is written:
Mechanism of local anesthetic: Preferentially bind to ACTIVATED Na+ channels so most effective in rapidly firing neuron.
My question: isn't it supposed to work on inactivated Na+ channel which is depolarized neurons as mentioned in Kaplan book?

2- It is mentioned in CNS pharmacology in Kaplan book page 147 that opiod works on smooth muscles where it relaxes longtidunal muscle and constricts circular muscles. So its effect on GU should be only urinary retention.
My question: why it is mentioned that there is urgency to void too?
Reply With Quote Quick reply to this message



  #2  
Old 11-08-2015
USMLE Forums Scout
 
Steps History: Step 1 Only
Posts: 23
Threads: 6
Thanked 11 Times in 6 Posts
Reputation: 21
Default word play

1) This is just some word play dont get confused by it ---> Activated Sodium channel = Inactivated Sodium Channel = Channel that has just fired (i.e. opened ) and now due to increased Em voltage has its inactivation gate shut down -- so it is ''inactivated'' ... Remember that there are 2 gates on the Na Channel , one for activation that is opened by a little increased Em voltage , and one for inactivation that is closed by a a lot increased Em voltage

2) Urgency to void due to overfilling of bladder because of contracted internal sphincter . You ''want'' to pee --> Overfilled bladder , but you can't --> contracted sphincter .. the life of the opioid abuser can be hard sometimes...
Reply With Quote Quick reply to this message
The above post was thanked by:
Albatoul Khaled (11-08-2015), datson (11-08-2015)
  #3  
Old 11-08-2015
USMLE Forums Scout
 
Steps History: Not yet
Posts: 33
Threads: 20
Thanked 3 Times in 2 Posts
Reputation: 13
Send a message via Skype™ to Albatoul Khaled
Default

I really appreciate it. Thanks
Reply With Quote Quick reply to this message



Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Location
Where you live. Leave blank if you don't want to tell.

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
How to answer Autonomic Pharmacology Questions mle2resident USMLE Step 1 Forum 10 10-06-2014 03:06 AM
Review of USMLE Pharmacology Questions in One Day!! Kahil USMLE Step 1 Study Partners 0 06-29-2014 02:30 PM
Belindalimm Daily Questions: Pharmacology #1 belindalimm USMLE Step 1 Forum 3 09-19-2012 08:46 PM
CNS practice questions S.bas.usmle USMLE Links & Free Ads 3 11-11-2011 11:49 AM
Two Pharmacology Questions? Seetal USMLE Step 1 Forum 4 07-26-2010 05:23 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)