HEMA

• Hematology

  Study of the formed (cellular) elements of the blood

  
• Hematology Section

  • Cellular elements, red blood cells (RBCs), white blood cells (WBCs), and platelets (Plts) are enumerated and classified in all body fluids and in the bone marrow
  • The MLT or MLS can detect disorders such as leukemia, anemia, other blood diseases, and infection and monitor their treatment

  
• Whole Blood

  • Most common body fluid analyzed in the hematology section
  • A mixture of cells and plasma
  • Obtained by using a collection tube with an anticoagulant to prevent clotting of the sample
• 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
• Plasma

  • Liquid portion of anticoagulated blood
  • Contains the protein fibrinogen
• Serum

  • Liquid portion of clotted blood
  • Fibrinogen in serum has already been used in the clotting of blood

  
• 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

  
• Erythrocytes

  • Donut-shaped wherein the outer portion of the cell will be prominent in color and the middle one will likely be stained or have less color
• 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
  • The number of lymphocytes increases in viral infections [dengue, measles, and common cold]
• 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
  • Not as rounded as the other leukocytes
  • Cannot mistake it from the others because of its size
  • A tissue monocyte is known as a macrophage
  • The number of monocytes increases in intracellular infections and tuberculosis
• 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 [largest cell in the bone marrow]
  • 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

  
• 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

  • Sometimes a part of the hematology section, but in larger laboratories, it is a separate section
  • Specimen: Plasma from light blue stopper tubes (Sodium citrate)
  • The overall process of hemostasis is evaluated; this includes: Platelets, Coagulation factors, Inhibitors, Blood vessels, Fibrinolysis, Anticoagulant therapy (heparin and Coumadin)

  
• Blood Smears

  • Needed for the microscopic of blood cells that is performed for the differential blood cell count, for special staining procedures, and for nonautomated reticulocyte counts
  • Should be collected before other samples to avoid platelet clumping
  • Obtained by: Dermal puncture, Venipuncture: EDTA (within 1 hour of collection)

  
• 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 [ends]