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.