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swedishstreakΜηχανική

22 Φεβ 2014 (πριν από 3 χρόνια και 4 μήνες)

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B
LOOD

A
NALYSIS

L
AB

Things to Know

H
EMATOCRIT

D
ETERMINATION


Hematocrit

refers to % of RBCs in a sample of
whole blood


A
hematocrit

of 48 means that 48% of the volume
of blood is red blood cells


The higher the
hematocrit
, the more RBCs
present in the sample


Hematocrit

is determined by spinning a
microcapillary

tube filled with a whole blood
sample in a special
microhematocrit

centrifuge.


This procedure separates blood cells from the
plasma and leaves a “
buffy

coat” layer of WBCs
between the heavier RBC layer and the lighter
plasma

D
ETERMINING

THE

HEMATOCRIT

VALUE


After centrifuging, measure the height of the
layer of RBCs in mm and divide by the height of
the initial column of blood to obtain the
percentage of RBCs


The percentage of WBCs can be determined by
comparing the height of the
buffy

coat to the
initial height of the blood column.


The average
hematocrit

for males is 47% and
42% for females


The upper limit is 55%


Lower than normal
hematocrit

= anemia


Higher than normal
hematocrit

=
polycythemia


Anemia


a condition in which insufficient
oxygen is transported to the body’s cells


Polycythemia



a condition caused by living at
high altitudes,
strenous

athletic training, and
tumors in the bone marrow

E
RYTHROCYTE

S
EDIMENTATION

R
ATE

(ESR)


Measures the settling of RBCs in a vertical,
stationary tube of blood during one hour


In a healthy individual, ESR only about 5 mm/hr


High ESRs indicate disease due to clumping
together of cells making them heavier and settle
faster


ESRs can be used to measure progression of a
disease (increase


worse; decrease


better)


Can be used to distinguish between angina
pectoris to myocardial infarction


H
EMOGLOGIN

(
HB
)
DETERMINATION


Used to determine possible causes of anemia


Normal blood contains average of 12
-
18 grams of
hemoglobin per 100 mm of blood


Increase occurs at high altitudes,
polycythemia
,
congestive heart failure, and chronic obstructive
pulmonary disease (COPD)


Decrease occurs with anemia, hyperthyroidism,
cirrhosis of the liver, renal disease, systemic
lupus
erythematosus
, and severe hemorrhage


Hb

content determined by stirring a sample of
blood with a wooden stick to break or
lyse

the
cells.


The intensity of the color of the color of the
sample is a result of the amount of
Hb

present


A
hemoglobinometer

compares the color of the
sample to standard values to determine the
hemoglobin content of the sample


Green light is used to view the sample because
the human eye is able to easily detect subtle
differences in green colors

B
LOOD

TYPING

Type

Antigens

Antibodies

A

A

Anti
-
B

B

B

Anti
-
A

AB

A and B

None

O

Neither A nor B

Anti
-
A, Anti
-
B


B
LOOD

T
YPING

Type

Donate

Receive

A

A, AB

A, O

B

B, AB

B, O

AB

AB only

A, B, AB, O

O

A, B, AB, O

O only

AB is the universal
recepient

O is the universal donor

R
H

FACTOR


Antigen discovered in Rhesus monkeys


If present,
Rh
+


If absent,
Rh
-


Rh
-

blood can be given to
Rh
+, but
Rh
+ cannot be
given to
Rh
-


Erythroblastosis

fetalis
: condition threatening
life of baby; occurs when baby is
Rh
+ and mother
is
Rh
-


Mother’s anti
-
Rh

antibodies
might

attack baby’s
RBCs

C
HOLESTEROL


Lipid substance essential for life


Important component of cell membranes, basis for
making steroid hormones, vitamin D, and bile salts


Produced in the human liver


Present in some foods of animal origin (milk, eggs,
meat)


Water insoluble, needs to be wrapped in protein
packages called lipoproteins to travel in the watery
blood from the liver and digestive organs to the cells
of the body


LDL (low density lipoprotein) is potential source of
damage to arteries causing plaque buildup; “bad
cholesterol”


HDL (high density lipoprotein) is “good cholesterol”


C
HOLESTEROL

D
ETERMINATION


Blood sample mixed with enzymes that produce a
colored reaction with cholesterol


Intensity of the color indicates the amount of
cholesterol present


Measured in mg/deciliter of blood


200 mg/deciliter = desirable


200
-
239 mg/deciliter = borderline high cholesterol


240 mg/deciliter = high blood pressure


“silent
-
killer” = can cause heart attack/stroke


Low levels may
indicate hypothyroidism