Lesson 3 C ESR Flashcards
RBC’s are suspended in plasma for 2 reasons:
1) the circulation of the blood keeps suspending RBCs because they are in motion all the time
2)Sialic acid (negative susbatnce ) on the surafce of the RBC
Factors that govern the speed of falling of RBC’s
1.The number of RBC(s) in the blood
The less the number of RBC(s) in the plasma the higher the speed of falling of
RBC(s) is. Therefore in a person with anemia, the speed of falling of RBC(s) will
be more. In a person with a very high RBC (condition known as polycythemia),
the speed of falling of RBC(s) becomes very low and the RBC(s) will not fall
anymore (plasma is so much low sedimentation stops).
2)Plasma viscosity
If the plasma is thicker, the speed of falling of RBC(s) will be less. The thicker
the plasma, the less the speed of falling of RBC(s). We can make the plasma
thicker by adding to it:
Albumin, globulins and fibrinogen.
So if the plasma proteins increase, the viscosity of the plasma increases and the
speed of falling of RBC(s) decreases as a consequence.
3)The red blood cell mass (this is the most important factor)
The greater the RBC mass is, the greater the speed of falling of RBC(s) is.
How can we increase the RBC mass?
rouleoux formation: in
which the broad surface of one RBC is over the broad surface of another RBC
(resembling a stack of coins).
PAGE 2
HIGHLIGHTED
What causes rouleaux formation?
Fibrinogen (most importnat factor ) and globulins (gamma globulins)
what doesnt cause rouleoux fomration at all?
albumin
Any condition which increases fibrinogen or γ globulins
will increase rouleaux
formation and therefore the sedimentation rate.
how do fibriongen and globulins cause rouleoux formation?
by removing the negative
charge of the RBC(s) and therefore allowing them to stick together
albumin for some reason
does not remove the negative charge of the RBC(s) and therefore, it
does not cause rouleaux formation
some of the conditions that increase the fibrinogen or γ globulins:
- Acute and Chronic infections (cause mostly an increase in γ globulins)
- Any tissue damage (Rheumatic fever, heart attack…) causes mostly an increase
in fibrinogen
Fibrinogen is an APR
Acute phase reactant (that increase in reponse to stressful or inflammatroy states taht occur with infections, surgery, trauma or other tissue necrosis)
γ globulins are produced by plasma cells so…
as such in cancers of plasma cells
such as Multiple Myeloma; there is a significant increase in γ globulins, leading to
a very high ESR level.
procedure for ESR is called
Weestergren’s method
we need a speciall pipetted called —– pipetted which is calibrated in — starting from —at the — up till – at the —
Westergren pipette/ mm/ zero/top/200/ bottom
you fill the westergren pipetter with—- till the mark—and —.
you leave the pipette —–for one hour and read the meniscus that separates the —-and record the —-
antcoaglated blood/ zero/and let it stand in a special rack for an hour/ exactly unshaken/ RBC-plasma layer / record the distance that erythrocytes have fallen after one hour in
mm /hour.
— and the — tend to have higher ESR levels
women and the elderly
Automated ESR method: it’s based on—– but it makes use of —to —-. the rate is —-and the test takes—/ the results are reported in—
the same principle/ inclined tubes/ accelerate the rate of sedimentation/optically determined (machine uses ligt sensors)/ 20 minutes/ mm/hour
