MLT 101: Microscope Lesson

Overview of Microscopy and Hematology

  • Recap of previous session regarding microscopy.

    • Engaged in hands-on activities with microscopes (~45 minutes).

    • Developed skills to transition between slides without extensive refocusing.

    • Discussed various blood-related slides observed (e.g., platelet morphology, malaria, sickle cell disease).

Introduction to Hematology

  • Transition from microscopy to hematology topic.

  • Emphasis on learning from provided material loaded in Blackboard and printed handouts (available Wednesday).

Blood Composition and Formation

  • Description of hematology as the study of blood and its forming tissues.

  • Primary blood-forming tissue identified as bone marrow.

    • For adults, major locations of active bone marrow include:

    • Axial skeleton (specifically pelvis and sternum).

    • Minimal active marrow is present in the vertebrae and proximal femur.

  • Development of blood in infants:

    • Prior to 7 months gestation, blood production occurs in the liver and spleen.

    • Post 7 months, the bone marrow takes over blood production but liver and spleen retain ability for extramedullary hematopoiesis in case of bone marrow failure.

Hematological Values and Measurements

  • Importance of memorizing hematological reference values and formulas.

  • Brief discussion of an anticipated math component in understanding hematological values.

Blood Components

  • Blood composition detailed as approximately 45% plasma and 55% formed elements.

    • Formed elements include three main types of cells:

    • Erythrocytes (RBCs)

      • Most abundant blood cells responsible for oxygen transport.

      • Normal erythrocyte counts:

      • Women: 4.2 to 5.4 imes 10^6 cells/microliter.

      • Men: 4.6 to 6.2 imes 10^6 cells/microliter.

      • Recent recommendations standardize to 4 to 6 imes 10^6 cells/microliter regardless of sex.

      • Hemoglobin content normal range: 12-18 g/dL.

      • Mature erythrocytes lack nuclei, presenting as round, biconcave discs.

      • Life span roughly 120 days; undergo hemolysis upon death, recycling components like iron to liver and marrow.

      • Abnormal shapes (poikilocytes) indicate pathology, including sickle cells.

    • Leukocytes (WBCs)

      • Types include neutrophils, lymphocytes, monocytes, eosinophils, and basophils, with varying functions in immunity and response to infection.

      • Normal leukocyte count 3.6 to 10.6 imes 10^3 cells/microliter.

      • Lifespan averages only a couple of days, requiring continuous production, with ratios of production favoring white cells (3-4 WBCs for each RBC).

    • Thrombocytes (Platelets)

      • Normal counts range from 150,000 to 450,000 platelets/microliter.

      • Function primarily in hemostasis; lifespan about 9 days.

      • Formed from megakaryocytes, which are noted as the largest cells in the body.

Hematological Indices

  • Critical parameters in evaluating red blood cell health and identifying anemias:

    • Mean Corpuscular Volume (MCV): The average volume of a red blood cell, calculated as rac{HCT}{RBCs} imes 10, normal range 76 to 100 femtoliters.

    • Mean Corpuscular Hemoglobin (MCH): Average hemoglobin content per red blood cell, calculated as rac{HGB}{RBCs} imes 10, normal range 26 to 34 picograms.

    • Mean Corpuscular Hemoglobin Concentration (MCHC): Ratio of hemoglobin to hematocrit, expressed as a percentage; calculated as rac{HGB}{HCT} imes 100; normal range 32 to 36%.

  • Importance of indices in diagnosing the cause of anemia (e.g., microcytic vs. macrocytic).

CBC and Differential

  • Components included in the Complete Blood Count (CBC):

    • Red blood cell count, hemoglobin, hematocrit, indices (MCV, MCH, MCHC), white blood cell count, platelet count.

    • The differential identifies and quantifies each type of white blood cell.

  • Significance of smear preparation techniques and appropriate tube usage (EDTA - purple or lavender).

Practical Application and Future Learning

  • Students challenged to generate quality blood smears; these slides are essential for differential analysis and must be prepared efficiently.

  • Review of parameters affecting slide adequacy, e.g., blood age concerning cell integrity.

  • Planned upcoming session to elaborate on coagulation and continue discussions on hematological components with hands-on practice.

Class Performance Recap

  • Notable achievements in cell bowl competition; acknowledgment of students performing well in cell identification tasks.

  • Recognition of individual student accomplishments and participation evaluated through email feedback.