Clasp Knife response - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
USMLE Articles
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

Thread Tools Search this Thread Display Modes
Old 06-24-2012
koolkiller88's Avatar
USMLE Forums Master
Steps History: Step 1 Only
Posts: 864
Threads: 62
Thanked 374 Times in 225 Posts
Reputation: 384
Default Clasp Knife response

Hello guys quite confused with this response mechanism. Can someone explain this in layman's language. As i already read in KLN and Wiki but not able to get the point exactly. Thanks.
One day i will infect these microbes and they will search for "Anti-MEbiotic"....
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Reply With Quote Quick reply to this message

Old 06-24-2012
Steps History: ---
Posts: 197
Threads: 9
Thanked 98 Times in 64 Posts
Reputation: 108

It's pretty simple actually.
1. In UMN palsy, there's increased A-gamma motor neuron firing to the muscle spindle, making them more sensitive to stretch. So you have exaggerated reflexes and greater resistance to passive stretch. thats what we call spasticity.
2. However that being said, the golgi tendon organs are still functional(they function through a spinal reflex(Ib and A-alpha), so they're not affected). So when the muscle tendon is stretched beyond a certain point, there's relaxation of the muscle giving rise to a sudden release, like a clasp knife.

I hope you've understood. This is explained beautifully in Ganong physiology if you want to read up further.
Reply With Quote Quick reply to this message
The above post was thanked by:
deh08001 (08-09-2016), elegantorchid (05-02-2014)


Quick Reply

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:
Please enter a password for your user account. Note that passwords are case-sensitive.
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.
Where you live. Leave blank if you don't want to tell.


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
Monocytic Response in Salmonella kenlee USMLE Step 1 Forum 3 08-02-2013 06:22 PM
Patient's Response Hope2Pass USMLE Step 1 Forum 6 08-17-2011 08:14 PM
ADH Response Question! bebix USMLE Step 1 Forum 17 06-30-2011 06:09 AM
TH1 Response and bacterial infection hana USMLE Step 1 Forum 9 06-20-2011 08:47 PM
A kid with a positive Chvostek response! bebix USMLE Step 1 Forum 15 06-02-2011 10:47 AM

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)