lecture 1

Question 1

what is hematology?

Answer 1

the science or study of blood and its diseases.

Question 2

how is the study of blood performed?

Answer 2

• By making use of instruments to determine certain parameters including
  cell counts and others.
• By taking blood and by examining it under the microscope.

Question 3

how much is the total blood volume in an adult?

Answer 3

the total blood volume is 5-6 liters or 7-8% of the body weight

Question 4

Blood is composed of two major constituents, what are they?

Answer 4

• (liquid part) plasma 55% –> 90% water + 10% proteins (albumin, globulin, fibrinogen), carbs, vitamins, lipids, hormones, enzymes, inorganic salts
• cellular components 45% –> Platelets, RBCs, WBCs

Question 5

• what are the anticoagulants used?
• how do they work?

Answer 5

• EDTA, citrate, and heparin
• they prevent the formation of fibrin from fibrinogen (responsible for blood clotting)

Question 6

the liquid portion of the blood has 2 names, what are they? and what is the difference between them?

Answer 6

• 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)

Question 7

why do erythrocytes have a reddish color?

Answer 7

due to to the presence of a pigment called hemoglobin (Hb)

Question 8

what are the different types of leukocytes?

Answer 8

neutrophils, lymphocytes. monocytes, eosinophils, basophils

Question 9

what are platelets, their function, and their scientific name?

Answer 9

• 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

Question 10

what is another name for thrombocytes?

Answer 10

platelets

Question 11

how blood specimens can be obtained?

Answer 11

by venipuncture or by skin puncture

Question 12

when we study blood, our interest is mainly in what blood constituent?

Answer 12

formed elements/ cellular components/ blood cells

Question 13

what are the different types of blood stains?

Answer 13

1. vital or supravital stains
2. regular stains
3. special stains

Question 14

vital or supravital stains key points

Answer 14

• used on living cells
• infrequently used

Question 15

regular stains key points

Answer 15

• 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

Question 16

what are some examples of fixatives?

Answer 16

1. methanol
2. ethanol
3. formalin
4. glacial acetic acid

Question 17

special stains key point

Answer 17

used to stain specific structures in the cell

Question 18

what does the romanowsky stain mainly consist of?

Answer 18

• basic dye (methylene blue) –> blue
• acidic dye (eosin) –> red
  + intermediate stains

Question 19

what are the standard romanowsky group of stains?

Answer 19

• leishman stain
• jenner stain
• may-grun wald stain
• wright stain
• giemsa
• granules

Question 20

which of the romanowsky group stains, stain best the cytoplasm

Answer 20

• leishman stain
• jenner stain
• may-grun wald stain
• wright stain

Question 21

which of the romanowsky group stains, stain best the nucleus

Answer 21

• giemsa
• granules

Question 22

we use the nucleus stain before cytoplasmic stains (T/F)

Answer 22

false, cytoplasmic before nucleus

Question 23

we stain first with wright stain and then giemsa (T/F)

Answer 23

true

Question 24

romanowsky type of stains act by which type of interaction?

Answer 24

chemical interaction with various substances present in the cell, depends on the pH of these susbstances

Question 25

basophilic key points

Answer 25

• 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

Question 26

acidophilic/ eosinophilic key points

Answer 26

• basic substances
• take up acidic dyes (eosin)
• stains red
  ex: proteins like Hb, cytoplasmic constituents, granules of eosinophils