Liver Blood Supply - 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 09-02-2012
venky2600's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 817 Times in 434 Posts
Reputation: 827
Send a message via Yahoo to venky2600
Liver Liver Blood Supply

A 36 yr old chronic alcoholic present with epigastric pain to the physician since 2 days...he describes the pain as colicky pain and associated with vomiting 3 episodes/day..on further examination he is diagnosed as fatty liver change...which of the following vessels supply majority of the blood and oxygen respectively to this patient's liver?

a) hepatic artery and portal vein
b) hepatic vein and portal vein
c) hepatic artery and hepatic vein
d) portal vein and hepatic artery
e) portal vein and hepatic vein
f) portal vein and superior mesenteric artery
Reply With Quote Quick reply to this message
The above post was thanked by:
belindalimm (09-02-2012), riya_rai84 (09-02-2012)



  #2  
Old 09-02-2012
USMLE Forums Guru
 
Steps History: Not yet
Posts: 375
Threads: 17
Thanked 131 Times in 81 Posts
Reputation: 147
Default

f) portal vein and superior mesenteric artery

Don't Know why , Its just a guess.
Reply With Quote Quick reply to this message
  #3  
Old 09-02-2012
USMLE Forums Newbie
 
Steps History: ---
Posts: 1
Threads: 0
Thanked 0 Times in 0 Posts
Reputation: 10
Default Liver Blood Supply

(d) portal vein (70%) &hepatic artery (30%)
Reply With Quote Quick reply to this message
 
  #4  
Old 09-02-2012
koolkiller88's Avatar
USMLE Forums Master
 
Steps History: Step 1 Only
Posts: 864
Threads: 62
Thanked 373 Times in 224 Posts
Reputation: 383
Default really nice question

In normal person
Liver have dual blood supply- portal veins and hepatic arteries

"Oxygen is provided from both sources; approximately half of the liver's oxygen demand is met by the hepatic portal vein, and half is met by the hepatic arteries." source- wiki

Now alchoholic, fatty changes. So i would estimate portal hypertension
d) portal vein and hepatic artery

Still lot of doubts. Answer will clear all.
__________________
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
The above post was thanked by:
belindalimm (09-02-2012)
  #5  
Old 09-02-2012
USMLE Forums Master
 
Steps History: 1+CK+CS
Posts: 1,039
Threads: 189
Thanked 561 Times in 319 Posts
Reputation: 571
Default my answer

d) portal vein and hepatic artery


the problem is in the liver so blood and oxygen supply will be the same as in a non-cirrhotic liver...
Reply With Quote Quick reply to this message
  #6  
Old 09-02-2012
Rookie's Avatar
USMLE Forums Guru
 
Steps History: 1+CK+CS
Posts: 394
Threads: 40
Thanked 218 Times in 99 Posts
Reputation: 228
Default

Quote:
Originally Posted by venky2600 View Post
A 36 yr old chronic alcoholic present with epigastric pain to the physician since 2 days...he describes the pain as colicky pain and associated with vomiting 3 episodes/day..on further examination he is diagnosed as fatty liver change...which of the following vessels supply majority of the blood and oxygen respectively to this patient's liver?

a) hepatic artery and portal vein
b) hepatic vein and portal vein
c) hepatic artery and hepatic vein
d) portal vein and hepatic artery
e) portal vein and hepatic vein
f) portal vein and superior mesenteric artery
...........
__________________
The Journey of thousand miles begins with a single step.
Reply With Quote Quick reply to this message
  #7  
Old 09-02-2012
venky2600's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 817 Times in 434 Posts
Reputation: 827
Send a message via Yahoo to venky2600
Correct Answer D is the right answer

yes, the correct answer is D) portal vein and hepatic artery

Exclusion method------SMA is not the blood supply to foregut...foregut is supplied by coeliac trunk---so,F can be eliminated
veins carry deoxygenated blood------veins in 2nd column are excluded A,B,C,E excludes---------leaves only 1 option

Explanation------------fatty liver change leads to ischemia of zone3 which is susceptible to hypoxia.....zone 3 consists of central vein which ultimately drained by hepatic vein..so, in fatty liver change there's no much change to arterial supply of liver
anatomical blood supply to liver is by 3/4th(70-75%) from portal vein tributaries and 1/4th(25-30%) from hepatic artery..
though portal vein supplies major supply to liver,but it's already been partially deoxygenated by the capillary bed of GI tract....so, the hepatic artery supplies 75% of oxygen supply to liver
Reply With Quote Quick reply to this message
  #8  
Old 09-02-2012
koolkiller88's Avatar
USMLE Forums Master
 
Steps History: Step 1 Only
Posts: 864
Threads: 62
Thanked 373 Times in 224 Posts
Reputation: 383
Default

Quote:
Originally Posted by venky2600 View Post
yes, the correct answer is D) portal vein and hepatic artery

Exclusion method------SMA is not the blood supply to foregut...foregut is supplied by coeliac trunk---so,F can be eliminated
veins carry deoxygenated blood------veins in 2nd column are excluded A,B,C,E excludes---------leaves only 1 option

Explanation------------fatty liver change leads to ischemia of zone3 which is susceptible to hypoxia.....zone 3 consists of central vein which ultimately drained by hepatic vein..so, in fatty liver change there's no much change to arterial supply of liver
anatomical blood supply to liver is by 3/4th(70-75%) from portal vein tributaries and 1/4th(25-30%) from hepatic artery..
though portal vein supplies major supply to liver,but it's already been partially deoxygenated by the capillary bed of GI tract....so, the hepatic artery supplies 75% of oxygen supply to liver
ok, I made a weird reasoning due to a sentence i read in wiki (i mentioned it above) but got the answer right (luckily). Meanwhile just for knowledge
Blood normally flows from portal vein to central vein (Is this because of greater pressure in portal vein then central vein?)
__________________
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
  #9  
Old 09-02-2012
venky2600's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 817 Times in 434 Posts
Reputation: 827
Send a message via Yahoo to venky2600
Post

Quote:
Originally Posted by koolkiller88 View Post
ok, I made a weird reasoning due to a sentence i read in wiki (i mentioned it above) but got the answer right (luckily). Meanwhile just for knowledge
Blood normally flows from portal vein to central vein (Is this because of greater pressure in portal vein then central vein?)
most probably, i guess...portal vein pressure is 5-10mmhg...hepatic vein pressure is 2-5 mmhg...
if there's other reason..plz explain it...
Reply With Quote Quick reply to this message
  #10  
Old 09-02-2012
koolkiller88's Avatar
USMLE Forums Master
 
Steps History: Step 1 Only
Posts: 864
Threads: 62
Thanked 373 Times in 224 Posts
Reputation: 383
Default

Quote:
Originally Posted by venky2600 View Post
most probably, i guess...portal vein pressure is 5-10mmhg...hepatic vein pressure is 2-5 mmhg...
if there's other reason..plz explain it...
Actually i was thinking, If somehow central vein pressure increases (pathologically) compared to portal vein. Then would it reverse the blood flow?

But i am not able to think of any situation like that.
__________________
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
  #11  
Old 09-02-2012
venky2600's Avatar
USMLE Forums Master
 
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 817 Times in 434 Posts
Reputation: 827
Send a message via Yahoo to venky2600
Post

Quote:
Originally Posted by koolkiller88 View Post
Actually i was thinking, If somehow central vein pressure increases (pathologically) compared to portal vein. Then would it reverse the blood flow?

But i am not able to think of any situation like that.
no, i guess
if hepatic vein pressure > 5/6 mm hg----it indicates portal vein hypertension
only chance could be budd chiari i guess
Reply With Quote Quick reply to this message



Reply

Tags
Anatomy-, Step-1-Questions

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
Varices Blood Supply tyagee USMLE Step 1 Forum 7 07-04-2012 05:10 AM
hepatic blood supply steps_8186 USMLE Step 1 Forum 1 03-04-2012 07:00 AM
Sensory supply of UL indigo USMLE Step 1 Forum 0 01-06-2012 10:38 AM
Difficulty memorizing brain blood supply! kdm0101 USMLE Step 1 Mnemonics 2 07-18-2011 07:10 PM
Liver disease that does not need a Liver Biopsy? FSUSTC USMLE Step 2 CK Forum 7 04-27-2011 05:07 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)