Intestinal Cellular Injury - 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 09-02-2012
venky2600's Avatar
USMLE Forums Master
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 814 Times in 434 Posts
Reputation: 824
Send a message via Yahoo to venky2600
GIT Intestinal Cellular Injury

A 56 yr old woman comes to a physician for diffuse mid abdominal pain..on p/e however, she has unimpressive pain on palpation..her lab values are remarkable for leukocytosis...if the pt. is untreated, which of the following characteristics would most likely be found in her intestinal cells..?

a) chromatin condensation at nuclear periphery
b) cytoplasmic shrinkage
c) lack of inflammation
d) myelin figures
e) membrane bound apoptotic bodies....

need some explanation.....
Reply With Quote Quick reply to this message

Old 09-02-2012
USMLE Forums Scout
Steps History: Not yet
Posts: 72
Threads: 8
Thanked 10 Times in 10 Posts
Reputation: 20

it was a nice Q so I cheated a bit before I concluded the answer....

the pt. is most prolly havin Gastroenteritis n hence will have intestinal cell necrosis....

a b e are features of apoptosis

c is wrong coz there will be some inflammation even if it is a non infective cause like ibd etc...

left with d...

but i had to google wat that is...
Reply With Quote Quick reply to this message
Old 09-02-2012
koolkiller88's Avatar
USMLE Forums Master
Steps History: Step 1 Only
Posts: 864
Threads: 62
Thanked 370 Times in 224 Posts
Reputation: 380
Default Myelin figures

I remember only one thing about myelin figure is that they are present in reversible injury. Where as A, B, E signifies apoptosis (as mentioned above)

It would be good that you explain more about myelin figures and all apototisis stages. As i always have one or other doubt in it.
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 09-02-2012
venky2600's Avatar
USMLE Forums Master
Steps History: 1+CK+CS+3
Posts: 1,186
Threads: 119
Thanked 814 Times in 434 Posts
Reputation: 824
Send a message via Yahoo to venky2600
Post D is the right answer

well , the correct answer is D) Myelin figures

exclusion method------A,B,C,E deals with apoptosis .easily excluded

explanation------pt. is suffering from classic case of ischemic bowel disease----ischemic bowel disease involves severe abdominal pain with no significant abdominal findings....ischemic changes most commonly leads to necrosis than programmed cell death(apoptosis)

it's really complex pathological process of hypoxic cell injury....i'll try to explain it briefly,but i may be correct me if i'm wrong....

Reversible changes-----hypoxic cell injury leads to decrease in ATP (coz, no oxygen for oxidative phosphorylation)
--only glycolysis takes place with activation of PFK(only 2ATP is produced)
--lactic acidosis( decreased pH---lead to denaturation of proteins)
--impairment of Na+-K+ -ATPase pump----Na+ and water permeability increases(cell swelling)
--ribosomal detachment(decrease protein synthesis)
--plasma membrane blebs

These above changes are often revertible if we given oxygen again...but sometimes, cells with damaged tissue will paradoxically die when oxygen is given------called as reperfusion injury(by free radicals/inflammation/complement activation)------ultimately leading to cell death via necrosis or apoptosis(irreversible processes)

Necrosis----is inflammatory process with absent nuclei and karyolysis
( nuclear fading---chromatin dissolution),
-mitochondrial permeability increases leading to vacuolization(myelin figures)-----myelin figures are composed of lipid bilayer resembling myelin sheath..found in cytoplasm or mitochondria vacuoles
-denaturation of enzymes and proteins,lysosomal lysis/rupture takes place..(due to severe lactic acidosis)....leading to autolysis(enzymatic degradation of cell) of cell..

Apoptosis----it is programmed cell death with absence of inflammatory involves caspase activation(via impaired Ca2+-ATPase pump--leading to influx of Ca2+).....

2 pathways......1) Extrinsic----TNF,FAS mediated apoptosis--CD95 acts as cellmembrane receptor--its activation(via TNF/FAS) lead to A)phospholipase stimulation releasing macrophages and phagocytosis (or)
B)caspase activation leading to DNA fragmentation(karyorrhexis---chromatin condensation into periphery,cytoplasmic shrinkage)---leads to formation of apoptotic bodies

2)Intrinsic------free radical injury with mitochondrial permeability---leads to cytochrome C release into cytosol.(along with APAF-1,an apoptosome)---caspase activation...act on P53/Bax/Bac----apoptosis

but, regarding myelin figures.....ROBBINS say it's the part of necrosis(which is irreversible process)...but rest other books say it's reversible.....
Reply With Quote Quick reply to this message
The above post was thanked by:
dockhi (09-03-2012), koolkiller88 (09-02-2012)


Cell-Biology-, Gastrointestinal-Tract-, Pathology-, Step-1-Questions

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
Intestinal part vulnerbable to ischemia! INCOGNITO USMLE Step 1 Forum 17 09-14-2012 07:55 AM
Intestinal Hormone secreted in hyperglycemia! INCOGNITO USMLE Step 1 Forum 6 09-14-2012 06:30 AM
Intestinal contractions and Intestinal hormones? sam01 USMLE Step 1 Forum 12 01-03-2012 07:19 AM
Cellular Transport? Yallah USMLE Step 1 Forum 2 04-07-2010 01:53 PM
Intestinal Micrograph USMLE Question Sabio USMLE Step 1 Forum 7 11-22-2009 02:17 PM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2016 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)