Please help me to answer the following question. Match the following
numbered words or phrases with the most appropriate lettered item.
Each lettered item can be used once, more than once, or not at all.


a. Premortem thrombi

b. Postmortem clots

c. Both

d. Neither 



1. Contain platelets

2. Contain fibrin

3. Gelatinous rather than friable

4. May become organized

Hi there Mashhour,

Thanks for an interesting question.  Using the search terms outlined
below, I first went to the University of Minnesota’s Pathology
Department to get a firm definition of the differences between thrombi
and clots:

"Thrombus:  A clotted mass of blood within intact vessels through the
complex interaction of the blood vessel walls, formed elements of the
blood (platelets) and plasma coagulants. A thrombus differs from a
clot, which forms in extravascular locations (e.g. hematoma) or only
involves the coagulation sequence (e.g. post-mortem clot, clot
formation in blood tubes). A thrombus can be distinguished from a
post-mortem clot both grossly and microscopically by its laminated
appearance (lines of Zahn) and by the presence of organization."
http://www.borg.labmed.umn.edu/PathClass/6101/embolism.html

Then I wanted more information on the organizational structure of the
lines of Zahn.  According to the University of Aukland Dept. of
Pathology:

"Layering of RBC's, fibrin, and WBC's is typical of a recent
pre-mortem thrombus, the so called lines of Zahn.”
http://www.health.auckland.ac.nz/webpath/labs/pulm2lab/pulm2a02.htm

This left the texture of the thrombosis vs. the clot.  The University
of Western Ontario supplied this definition:

"Thrombosis is the inappropriate or pathological formation of a solid
mass from the constituents of the blood within living blood vessels or
the heart; the resultant mass is termed a thrombus. The thrombus is
formed by a complex process involving the interaction of blood vessel
walls, the formed elements of the blood, (notably the platelets) and
the plasma factors that constitute the blood-clotting system. In
contrast, a blood clot involves only the coagulation sequence either
outside blood vessels or after death. Thrombi that arise in the
rapidly moving arterial or cardiac circulation are composed largely of
fibrin and platelets with only a few trapped red and white cells;
however, with very sluggish venous flow, thrombi may resemble blood
clots."

and...

“Thrombi must be differentiated from postmortem clots: the thrombus is
generally somewhat friable and firm, whereas the postmortem clot is
usually a rubbery, gelatinous coagulum with a cyanotic dark red
(current jelly) colour or it may have a supernatant portion of
coagulated clear plasma (chicken fat).”
http://www.uwo.ca/pathol/MedsI/Hemodynamic/hthrombosis.html

Given the above, your answers are:

1.	c; Both contain platelets 
2.	a; Only pre-mortem thrombi contain fibrin
3.	b; Postmortem clots, due to the lack of fibrin, are gelatinous
4.	a; Only pre-mortem thrombi may become organized

Thanks again for an interesting question!  If you need clarification,
please don’t hesitate to use the “Request Clarification” button.

--Kutsavi

SEARCH TERMS:

pre mortem thrombus
://www.google.com/search?hl=en&lr=&ie=UTF-8&q=pre+mortem+thrombus&spell=1

postmortem thrombus gelatinous friable
://www.google.com/search?hl=en&lr=&ie=ISO-8859-&q=postmortem+thrombus+gelatinous+friable&btnG=Google+Search

clot thrombus fibrin
://www.google.com/search?hl=en&lr=&ie=ISO-8859-&q=clot+thrombus+fibrin&btnG=Google+Search

the answers provided were incorrect.

the answers are 1) A, 2) C, 3) B, 4) A.

the explanations are as follows:
     1) thrombi contain platelets, while blood clots do not.
     2) both thrombi and blood clots contain fibrin (it is what holds
them together), as well as erythrocytes (red blood cells) and
leukocytes (white blood cells).
     3) thrombi are firm and friable because they are formed in layers
due to flowing blood, while blood clots tend to be more disorganized
since they form in environments deficient in certain necessary
elements (such as static blood or outside the vascular system).
     4) organization is an active process whereby the body (the LIVING
body) sort of "absorbs" or "incorporates" the thrombus into tissue.