Cardiovascular Physiology - 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 04-03-2015
USMLE Forums Newbie
 
Steps History: Not yet
Posts: 9
Threads: 3
Thanked 1 Time in 1 Post
Reputation: 11
Default Cardiovascular Physiology

Hi! Can somebody explain to me why right atrial pressure increases when there is a decrease in cardiac output? From the way I think about it, it should decrease, because first of all your flow is less, so you want the pressure drop to be high so that venous blood can get back to the heart, which means you will want to keep it much less than Psf. (Q dir prop to P1-P2/R)
Reply With Quote Quick reply to this message



  #2  
Old 04-03-2015
Hassan8's Avatar
USMLE Forums Addict
 
Steps History: Step 1 Only
Posts: 142
Threads: 27
Thanked 51 Times in 33 Posts
Reputation: 61
Default

If the cardiac output is less that means more blood in the heart which leads to increased right atrial pressure.
Reply With Quote Quick reply to this message
  #3  
Old 04-03-2015
Hassan8's Avatar
USMLE Forums Addict
 
Steps History: Step 1 Only
Posts: 142
Threads: 27
Thanked 51 Times in 33 Posts
Reputation: 61
Default

I think you are being confused by the vascular function curves. The way of looking at them is that you divide the diagram into 2 parts:
1. VENOUS RETURN vs RIGHT ATRIAL PRESSURE :
So in this part when the right atrial pressure decreases starting from maximum and moving towards the left the venous return will increase because you know blool flows from high pressure to low pressure.

2. CARDIAC OUTPUT vs EDV
This part of the curve is essentially the same as frank starling curve which says that as you increase the edv the cardiac output will increase.

Now the heart will operate at the point of intersection of these two curves. This is the easiest way to look at those curves. Hope this clears it up.
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
cardiovascular physiology usmle778 USMLE Step 1 Forum 0 03-23-2014 02:44 PM
Cardiovascular Physiology Curves hennizzzi USMLE Step 1 Forum 7 05-16-2013 09:19 PM
Cardiovascular Physiology Calculation! bunny USMLE Step 1 Forum 4 03-20-2012 08:17 PM
Cardiovascular physiology - tricky question! bebix USMLE Step 1 Forum 16 08-01-2011 07:20 PM
Supine to standing; Cardiovascular physiology bebix USMLE Step 1 Forum 19 06-29-2011 12:24 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)