HEMATOLOGY

• HEMATOLOGY - Study of the formed (cellular) elements of the blood
• WHOLE BLOOD

  • Most common body fluid analyzed in the hematology section

  • A mixture of cells and plasma
• BLOOD - The body’s main fluid for transporting nutrients, waste products, gases, and hormones through the circulatory system
• Average blood volume for adults - 5-6 liters
• Component of Whole blood in Purple Tube

  • Plasma
  • White Blood Cells and Platelets
  • Red blood Cells
• Components of Whole blood in Red top tube

  • Serum
  • Clotted blood
• Plasma – liquid portion of anti-coagulated blood
• Serum – liquid portion of clotted blood
• Fibrinogen - in serum has already been used in the clotting of blood
• Plasma comprises approximately 55% of the total blood volume
• ERYTHROCYTES

  • Red blood cells
  • Are anucleate biconcave disks that are approximately 7.2 microns in diameter
  • Erythrocytes contain the protein hemoglobin to transport oxygen and carbon dioxide
  • Life span: 120 days
• LEUKOCYTES

  • White blood cells

  • Provide immunity to certain diseases by producing antibodies and destroying harmful pathogens by phagocytosis

  • Normal number: 4,500 to 11,000 per microliter of blood
• White blood cell count – determines the number of all WBC present in the blood
• Differential cell count – determines the percentage of each type of leukocyte
• NEUTROPHILS

  • The most numerous leukocytes (40-60%)
  • Provide protection against infection through phagocytosis
  • Called “segmented” or “polymorphonuclear cells”
  • Nuclei of the neutrophils has 3-5 segments
  • Increases in bacterial infection
• LYMPHOCYTES

  • The second most numerous leukocytes (20-40%)
  • Provide the body with immune capability by means of B and T lymphocytes
  • Has a large round purple nucleus with a rim of sky blue cytoplasm
• B-lymphocytes - antibodies
• T-lymphocytes - active search and destroy of antigens
• MONOCYTES

  • 3-8%

  • Largest circulating leukocytes

  • Act as a powerful phagocytes to digest foreign material

  • The cytoplasm has a fine blue-gray appearance with vacuoles and a large, irregular nucleus
• A tissue monocyte is known as a macrophage
• EOSINOPHILS

  • 1-3%

  • Red orange granules, and the nucleus has only two lobes [bilobes]

  • Detoxify foreign proteins and increase in allergies, skin infections, and parasitic infections
• BASOPHILS

  • 0-1%

  • Least common of the leukocytes

  • The cytoplasm contains large granules that stain purple-black

  • Release histamine in the inflammation process and heparin to prevent abnormal blood clotting
• THROMBOCYTES

  • Platelets

  • Small, irregularly shaped disks formed from the cytoplasm of very large cells in the bone marrow called the megakaryocytes

  • Life span: 9-12 days

  • Average number: between 140,000 and 440,000 per microliter of blood

  • Play a vital role in blood clotting in all stages of the coagulation mechanism
• megakaryocytes - largest cell in the bone marrow
• COMPLETE BLOOD COUNT (CBC)

  • The primary analysis performed in the hematology section

  • Very often it is ordered on a STAT basis

  • Series of different tests
• COAGULATION SECTION - Tests here is not as open as the hematology

  section
• BLOOD SMEAR

  • Smooth film of blood that covers approximately one-half to two thirds of the slide

  • Does not contain ridges or holes

  • Has a lightly feathered edge without streaks
• Uneven distribution of blood (ridges)

  • Increased pressure on the spreader slide
  • Movement of the spreader slide not continuous
  • Delay in making slide after drop is placed on slide
• Holes in the smear

  • Dirty slides
  • Contamination with glove powder
• No feathered edge

  • Spreader slide not pushed the entire length of the smear slide
• Streaks in the feathered edge

  • Chipped or dirty spreader slide
  • Spreader slide not placed flush against the smear slide
  • Pulling the spreader slide into the drop of blood so that the blood is pushed instead of pulling
  • Drop of blood starts to dry out owing to delay in making smear
• Smear too think and short

  • Drop of blood is too big
  • Angle of spreader slide is greater than 40 degrees
• Smear too thin and long

  • Drop of blood is to small
  • Angle of spreader slide is less than 30 degrees
  • Spreader slide pushed too slowly