CO and Oxygen dissociation curve - 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 10-14-2012
USMLE Forums Scout
 
Steps History: 1+CK+CS
Posts: 85
Threads: 13
Thanked 22 Times in 15 Posts
Reputation: 32
Help CO and Oxygen dissociation curve

FA in ODC says that CO decreases the oxygen binding capacity with a left shift in the oxyen -hemoglobin dissociation curve.Isn't that oposite an increase in the oxygen binding capacity causes the curve to shift to the left and CO increases the afinity of the unbound haemoglobin.PLEASE SOMEONE RESPOND!
__________________
preeti
Reply With Quote Quick reply to this message



  #2  
Old 10-14-2012
dr.ali2011's Avatar
USMLE Forums Scout
 
Steps History: Not yet
Posts: 96
Threads: 10
Thanked 24 Times in 23 Posts
Reputation: 34
Send a message via Skype™ to dr.ali2011
Default

As Hb has 4 pockets to bind O2, suppose CO binds to 2 pockets so it will affect the other 2 pockets to hold the already bound O2 tightly,it competes the new O2 to bind with Hb but prevents the already bound O2 to dissoaciate, so in the presence of CO the curve shifts left.
__________________
If you do not hope, you will not find what is beyond your hopes.
Reply With Quote Quick reply to this message
The above post was thanked by:
preeti617 (10-15-2012)
  #3  
Old 10-14-2012
Kabutar111's Avatar
USMLE Forums Guru
 
Steps History: Not yet
Posts: 414
Threads: 30
Thanked 86 Times in 69 Posts
Reputation: 96
Send a message via Skype™ to Kabutar111
Default

affinity determines the curve not the capacity
__________________
There is no shortcut to SUCCESS ,and there is no excuse for FALIURE - by Kabutar111
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
The above post was thanked by:
preeti617 (10-15-2012)
  #4  
Old 10-14-2012
USMLE Forums Scout
 
Steps History: 1+CK+CS
Posts: 85
Threads: 13
Thanked 22 Times in 15 Posts
Reputation: 32
Help ODC

So, this is a misprint in FA !
Quote:
Originally Posted by Kabutar111 View Post
affinity determines the curve not the capacity
__________________
preeti
Reply With Quote Quick reply to this message
  #5  
Old 10-14-2012
Kabutar111's Avatar
USMLE Forums Guru
 
Steps History: Not yet
Posts: 414
Threads: 30
Thanked 86 Times in 69 Posts
Reputation: 96
Send a message via Skype™ to Kabutar111
Default

Quote:
Originally Posted by preeti617 View Post
So, this is a misprint in FA !
No it's not a mistake
CO dec binding capacity but the affinity of the rest of the oxygen is increased
__________________
There is no shortcut to SUCCESS ,and there is no excuse for FALIURE - by Kabutar111
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
The above post was thanked by:
preeti617 (10-15-2012)
  #6  
Old 10-14-2012
USMLE Forums Scout
 
Steps History: 1+CK+CS
Posts: 70
Threads: 8
Thanked 46 Times in 28 Posts
Reputation: 56
Default

CO has 200 times more affinity for Hb than O2 for Hb, therefore decrease O2 binding capacity of Hb, decrease O2 saturation & decrease O2 content of blood ---> decrease O2 unloading to tissues(b'coz Hb holds on to remaining O2)----> left shift on ODC.
Reply With Quote Quick reply to this message
The above post was thanked by:
preeti617 (10-15-2012)



Reply

Tags
Physiology-

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
P50 and O2 Hb dissociation curve flowerlady USMLE Step 1 Forum 1 12-23-2011 04:50 PM
dissociation curve shift scopusmount USMLE Step 1 Forum 6 11-03-2011 10:15 AM
Hb Oxygen Dissociation Curve Question INCOGNITO USMLE Step 1 Forum 12 06-14-2011 01:47 PM
Oxygen Dissociation Curve for Carbon Monoxide and MetHemoglobin Jackstraw1589 USMLE Step 1 Forum 5 05-26-2011 01:16 AM
Oxygen dissociation curve to the left or to the right? devareddy USMLE Step 1 Forum 6 07-27-2010 07:18 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)