hematology

  • Introduction

    • Importance of engagement during lectures

    • Blood as a component of the circulatory system

  • Blood Overview

    • Blood is considered a connective tissue.

    • Average human blood volume: 4 to 6 liters, approximately 5 liters.

    • Composition: 2.6 liters in plasma, 2.4 liters in formed elements.

  • Centrifugation of Blood

    • When blood is centrifuged, it creates three layers based on density:

    • Top Layer (Plasma): 55% of blood, 91-92% is water, 7% proteins (albumin, globulins, fibrinogen, prothrombin), 2% ions, nutrients, waste, gases, and regulatory substances.

    • Middle Layer (Buffy Coat): Contains platelets (thrombocytes) and leukocytes (white blood cells). Thrombocytes: 40,000 to 340,000; Leukocytes: 5,000 to 10,000.

    • Bottom Layer (Erythrocytes): Red blood cells, 4 to 6 million per cubic millimeter.

  • Blood and pH Regulation

    • Blood is alkaline with a pH range of 7.35 to 7.45.

    • Below 7.35: acidosis; above 7.45: alkalosis.

    • Mechanisms to maintain pH: kidneys, lungs, blood buffers.

  • Blood Types

    • Four blood types: A, B, AB, and O.

    • Key Terms:

    • Antigen: Marker on red blood cells.

    • Antibody: Substance produced in the blood.

    • Type A: Antigen A, Anti-B antibodies

    • Type B: Antigen B, Anti-A antibodies

    • Type AB: Antigens A and B, no antibodies (universal recipient)

    • Type O: No antigens, Anti-A and Anti-B antibodies (universal donor)

  • Rh Factor

    • Positive blood type can receive from both positive and negative, but can only give to positive.

    • Negative can give to both but can only receive negative.

    • Rh incompatibility can cause erythroblastosis fetalis if a Rh negative mom has a Rh positive baby.

  • Blood Cells Composition

    • Red Blood Cells (Erythrocytes):

    • Shape: biconcave disk, no nucleus, lifespan ~120 days.

    • Main function: oxygen transport via hemoglobin (contains iron).

    • Types based on hemoglobin levels:

      • Normochromic: normal color

      • Hypochromic: low hemoglobin

      • Hyperchromic: high hemoglobin

      • Microcytic: small

      • Macrocytic: large

    • Hematocrit: Percentage of red blood cells.

    • Conditions:

      • Polycythemia: too many red blood cells (thick blood).

      • Anemia: low red blood cell count or hemoglobin.

      • Types: hemorrhagic, aplastic, deficiency, hemolytic, etc.

  • White Blood Cells (Leukocytes)

    • Count: 5,000 to 10,000. Less than 5,000 = leukopenia (risk of infections), more than 10,000 = leukocytosis (active infection or leukemia).

    • Types of leukocytes:

    • Granular: Neutrophils (phagocytes), Eosinophils (parasites/allergy), Basophils (allergic reactions, produce heparin).

    • Agranular: Monocytes (largest, macrophages), Lymphocytes (B cells for antibodies, T cells do not produce antibodies).

  • Platelets (Thrombocytes)

    • Function: clotting, prevent bleeding.

    • Process:

    • Prothrombin activator -> prothrombin -> thrombin -> fibrinogen -> fibrin (blood clot formation).

    • Blood Clotting Disorders:

    • Hemophilia (X-linked, missing factor VIII).

    • Thrombocytopenia (low platelet count).

  • Conclusion

    • Recap of important components of blood: erythrocytes, leukocytes, thrombocytes, their functions, and related disorders.

    • Remember key term: Neutrophils.