lecture 1 Flashcards
what is hematology?
the science or study of blood and its diseases.
how is the study of blood performed?
- By making use of instruments to determine certain parameters including
cell counts and others. - By taking blood and by examining it under the microscope.
how much is the total blood volume in an adult?
the total blood volume is 5-6 liters or 7-8% of the body weight
Blood is composed of two major constituents, what are they?
- (liquid part) plasma 55% –> 90% water + 10% proteins (albumin, globulin, fibrinogen), carbs, vitamins, lipids, hormones, enzymes, inorganic salts
- cellular components 45% –> Platelets, RBCs, WBCs
- what are the anticoagulants used?
- how do they work?
- EDTA, citrate, and heparin
- they prevent the formation of fibrin from fibrinogen (responsible for blood clotting)
the liquid portion of the blood has 2 names, what are they? and what is the difference between them?
- plasma and serum
1- plasma contains fibrinogen (usage of anticoagulants/ no blood coagulation)
2- serum has no fibrinogen (blood coagulates, formation of fibrin from fibrinogen)
why do erythrocytes have a reddish color?
due to to the presence of a pigment called hemoglobin (Hb)
what are the different types of leukocytes?
neutrophils, lymphocytes. monocytes, eosinophils, basophils
what are platelets, their function, and their scientific name?
- small structures
- not true cells
- cytoplasmic fragments of giant cells (megakaryocytes: cells with a giant nucleus)
- the function of platelets is in the process of sealing an injured blood vessel/ in blood clotting/ forming a clot or a thrombus
- scientific name is thrombocytes
what is another name for thrombocytes?
platelets
how blood specimens can be obtained?
by venipuncture or by skin puncture
when we study blood, our interest is mainly in what blood constituent?
formed elements/ cellular components/ blood cells
what are the different types of blood stains?
- vital or supravital stains
- regular stains
- special stains
vital or supravital stains key points
- used on living cells
- infrequently used
regular stains key points
- used on dead cells
- cells must be killed very rapidly and preserved (fixation of cells)
- fixing should be fast in order to prevent any changes happening to the cells before it dies
what are some examples of fixatives?
- methanol
- ethanol
- formalin
- glacial acetic acid
special stains key point
used to stain specific structures in the cell
what does the romanowsky stain mainly consist of?
- basic dye (methylene blue) –> blue
- acidic dye (eosin) –> red
+ intermediate stains
what are the standard romanowsky group of stains?
- leishman stain
- jenner stain
- may-grun wald stain
- wright stain
- giemsa
- granules
which of the romanowsky group stains, stain best the cytoplasm
- leishman stain
- jenner stain
- may-grun wald stain
- wright stain
which of the romanowsky group stains, stain best the nucleus
- giemsa
- granules
we use the nucleus stain before cytoplasmic stains (T/F)
false, cytoplasmic before nucleus
we stain first with wright stain and then giemsa (T/F)
true
romanowsky type of stains act by which type of interaction?
chemical interaction with various substances present in the cell, depends on the pH of these susbstances
basophilic key points
- acidic substances
- take up basic dyes (methylene blue)
- stains blue
ex: RNA, DNA, cytoplasmic proteins, granules of basophils - the more there is RNA, the more bluish the cell
acidophilic/ eosinophilic key points
- basic substances
- take up acidic dyes (eosin)
- stains red
ex: proteins like Hb, cytoplasmic constituents, granules of eosinophils
