MA

A_P_Lab_Exercise_2_-_Blood__2024_.docx

Objectives

  • Differentiate between major populations of leukocytes in human blood.

  • Understand the function of each major population of white blood cells (WBC).

  • Identify the major role of fibrinogen in blood coagulation.

  • Differentiate between formed and fluid elements in blood.

  • Measure hematocrit and hemoglobin levels in a blood sample.

Blood Composition

  • Blood is a complex tissue that transports materials throughout the body.

  • Made up of formed elements (cells) and fluid elements (plasma).

  • Major components:

    • Erythrocytes (RBCs): High abundance, responsible for O2 transport.

    • Leukocytes (WBCs): Fight infections.

Blood Types

  • Four major blood types determined by A, B, AB, or O antigens on RBC surfaces.

    • Blood type is crucial during transfusions.

    • O-: Universal donors; compatible with any blood type.

    • AB+: Universal recipients; can receive from all blood types.

White Blood Cells

Types of WBCs

  • Granulocytes:

    • Contain granules rich in digestive enzymes.

    • Major types:

      • Neutrophils (55-70%): Most common, respond to bacterial infection.

        • Recognizable by polymorphic nucleus and pale pink cytoplasm.

        • Elevated in bacterial infections.

      • Eosinophils (1-4%): Respond to parasites and allergy responses.

        • Identified by bilobed nucleus and red-staining granules.

      • Basophils (0.5-1%): Involved in inflammatory responses; nucleus often obscured by granules.

  • Lymphocytes:

    • Sizeable non-granulocyte WBCs, crucial for adaptive immunity.

    • Types:

      • T-cells: Combat intracellular pathogens.

      • B-cells: Produce antibodies against pathogens.

  • Monocytes:

    • Largest WBCs with kidney-bean shaped nuclei.

    • Differentiate into macrophages in tissues; highly phagocytic.

Hemostasis and Fibrinogen

  • Hemostasis: Process of stopping bleeding.

    • Fibrinogen is converted to fibrin to form blood clots.

  • Coagulation observed in lab through clotted samples where fibrin strands can be visualized.

  • Hemoglobin (Hgb) carries O2 in RBCs, with each molecule capable of binding 4 O2 molecules.

  • Normal Hgb levels:

    • Females: 12-16 g/dL

    • Males: 13.5-17.5 g/dL

Lab Procedures

Part A: ABO Blood Typing

  • Review blood typing methods and materials.

  • Ensure to avoid cross-contamination of blood samples.

Part B: Blood Staining and WBC Enumeration

  • Proper blood smear techniques for microscope examination.

    • Count and categorize 100 WBCs based on morphology.

Part C: Hemoglobin Determination

  • Measure Hgb levels using a colorimetric method based on drop comparison with a color chart.

Part D: Sickle Cell Anemia

  • Observe and analyze a blood smear for sickle cell characteristics.

Part E: Check-off

  • Confirm identification of specific blood components before leaving lab.

Post-Lab Questions

  • Analyze data regarding blood types and universal donors/recipients.

  • Discuss differences in normal and sickle cell shapes and their physiological impacts.