Introduction Flashcards
FUNCTION OF BLOOD:
• Transports oxygen from lungs to tissues
• Clears tissues of carbon dioxide
• Transports glucose, proteins, and lipids
• Moves wastes to the liver and kidneys.
Plasma provides _______that protect vessels from trauma and maintain circulation.
coagulation enzymes
THREE CATEGORIES OF BLOOD CELLS
- Red blood cells (RBCs) or erythrocytes
- White blood cells (WBCs) or leukocytes
- Platelets (PLTs), or thrombocytes
COMPLETE BLOOD COUNT (CBC)
- is performed on automated blood cell analyzers and includes the…
RBC, WBC, and platelet measurements
Out-patient Department
• Done in the ___
• A dedicated___is present.
• Also known as “____”
• No_____ is needed
extraction area
phlebotomy chair
walk-ins
schedule/appointment
In-Patient Department
• Done in_____
• Some hospitals establish ____for the phlebotomist to collected blood
• Not unless STAT sample is needed.
bedside of patient ER, OR, Wards, ICU
warding
time
may be automated, relying on car code or radiofrequency identification technology, thus reducing instances of identification error.
Accession
Processing most laboratories employ ______to generate the CBC.
automated blood cell analyzers
When one of the results from the blood cell analyzer is abnormal, the instrument provides an indication of this, sometimes called a____
flag
Releasing of results
Should there be abnormalities in the result, or such circumstances where results are too high or too low compared to the reference ranges, it is just that the medical technologist should perform______
Manual CBC
RBCs are anucleate, biconcave, discoid cells filled with a reddish protein,____, which transports oxygen and carbon dioxide
hemoglobin
RBCs
- appear ____and measure ____in diameter with a ____ that occupies one-third of their center, reflecting their biconcavity
salmon pink
7 to 8 mm
zone of pallor
Polycythemia…
means an increased RBC count reflecting increased circulating RBC mass, a condition that leads to hyperviscosity
microscopists counted RBCs bv carefully pipetting a tinv aliquot of whole blood and mixing it with____
• Normal saline matches the osmolality of blood; consequently, the suspended RBCs retained their intrinsic morphology, neither swelling nor shrinking
0.85% (normal) saline
- A_____ dilution was typical for RBC counts and a glass pipette designed to provide this dilution, the Thoma pipette, was used routinely until the advent of automation.
1:200
- The diluted blood was transferred to a glass counting chamber called a_____
hemacytometer
Hemoglobin measurement relies on a weak solution of
potassium cyanide and potassium ferricyanide, called Drabkin reagent
- An aliquot of whole blood is mixed with a measured volume of Drabkin reagent, hemoglobin is converted to stable_____
• the absorbance or color intensity of the solution measured spectrophotometer at _____wavelength
cyanmethemoglobin (hemiglobincyanide)
540 nm
HEMATOCRIT DETERMINATION
-> also called
packed cell volume (PCV)
is a light-colored layer between RBCs and plasma and contains WBCs and platelets
• excluded from the hematocrit determination.
buffy coat
Hct normal ratio
50%
RBC INDICES
- The medical laboratory professional may use the three numerical results
• (3), to compute the RBC indices (4)
RBC count, HGB, and HCT
mean cell volume (MCV), mean cell hemoglobin (MCH), and mean cell hemoglobin concentration (MCHC)
- Extreme RBC volume variability is visible on the Wright-stained blood film as variation in diameter and is called
anisocytosis
provide stable measurements for internal quality control of automated blood cell analyzers
RBC indices
are used in nearly all clinical laboratories to generate these data, although visual examination of Wright-stained blood film is essential to verify abnormal results
Automated blood cell analyzers
MCV formula
HCT/RBC x 10
MCH formula
HGB/ RBC x 10
MCHC formula
HGB/ HCT x 100
To accomplish a blood film examination, the microscopist prepares a “_____” blood film on a glass microscope slide, allows it to dry, and fixes and stains it using____
wedge-prep
Wright or Wright-Giemsa stain.
The microscopist systematically reviews. identifies. and tabulates 100 (or more) WBCs to determine their percent distribution
This process is referred to as_____
WBC differential (“diff’)
the typical dilution is____, and the diluent is a dilute acid solution.
1:20
A decreased WBC count is called____
An increased WBC count is called____
leukopenia
leukocytosis
