1. General Pathology
    2. 1. The Cell as a Unit of Health and Disease
    2. Cellular Response to Stress and Toxic Insults
    3. Inflammation and Repair
    4. Hemodynamic Disorders, Thromboembolic Disease, and Shock
    5. Genetic Disorders
    6. Diseases of the Immune System
    7. Neoplasia
    8. Infectious Diseases
    9. Environmental and Nutritional Diseases
    10. Diseases of Infancy and Childhood
  2. Systemic Pathology: Diseases of Organ Systems
    3. 11. Blood vessels
    12. The Heart
    13. Diseases of White Blood Cells, Lymph Nodes, Spleen, and Thymus
    14. Red Blood Cell and Bleeding Disorders
    15. The Lung
    16. Head and Neck
    17. The Gastrointestinal Tract
    18. Liver and Gallbladder
    19. The Pancreas
    20. The Kidney
    21. The Lower Urinary Tract and Male Genital System
    22. The Female Genital Tract
    23. The Breast
    24. The Endocrine System
    25. The Skin
    26. Bones, Joints, and Soft Tissue Tumors
    27. Peripheral Nerves and Skeletal Muscles
    28. The Central Nervous System
    29. The Eye
General Pathology
4. Hemodynamic Disorders, Thromboembolic Disease, and Shock
HEMODYNAMIC DISORDERS, THROMBOEMBOLIC DISEASE, AND SHOCK
Edema and Effusions
▢ Increased Hydrostatic Pressure:
▢ Reduced Plasma Osmotic Pressure:
▢ Sodium and Water Retention:
▢ Lymphatic Obstruction:
Hyperemia and Congestion
Hemostasis, Hemorrhagic Disorders, and Thrombosis
Hemostasis
▢ Platelets:
▢ Coagulation Cascade:
▢ Endothelium:
Hemorrhagic Disorders
Thrombosis
▢ Definition: Inappropriate activation of normal hemostatic mechanisms, resulting in formation of a blood clot in an uninjured vessel or after minimal injury.
▢ Mechanism of formation (Virchow's Triad):
❖ 1. Endothelial Injury:
◉ Description: Damage to the endothelium promotes thrombus formation, especially in heart and arterial circulation.
◉ Causes:
  1. Vasculitis
  2. Hypertension
  3. Turbulent blood flow
  4. Bacterial endotoxins
  5. Homocystinuria
  6. Hypercholesterolemia
  7. Radiation
❖ 2. Alterations in Normal Blood Flow:
◉ Description: Turbulence leads to arterial thrombosis; stasis contributes to venous thrombosis.
◉ Associated Conditions:
  1. Aneurysms
  2. Myocardial infarction
  3. Hyperviscosity syndromes (e.g., polycythemia)
  4. Sickle cell anemia
❖ 3. Hypercoagulability:
◉ Description: Abnormally increased tendency to develop thrombosis.
◉ Types:
◈ Primary (Genetic):
  1. Factor V Leiden mutation (most common)
  2. Antithrombin III deficiency
  3. Protein C or S deficiency
  4. Defects in fibrinolysis
  5. Homocysteinemia
  6. Prothrombin gene mutation
  7. Mutation in MTHFR gene
◈ Secondary (Acquired):
  1. Prolonged bed rest or immobilization
  2. Homocysteinemia
  3. Tissue damage (e.g., surgery, fractures, burns)
  4. Cancer
  5. Myocardial infarction
  6. Prosthetic cardiac valves
  7. Disseminated intravascular coagulation (DIC)
  8. Heparin-induced thrombocytopenia (HIT)
  9. Antiphospholipid antibody syndrome
▢ Morphology:
❖ Size and Shape: Varies depending on site of origin and underlying cause.
❖ Lines of Zahn:
◉ Description: Gross and microscopic laminations seen in thrombi.
◉ Components:
◈ Pale layers: Platelet and fibrin deposits.
◈ Dark layers: Red cell-rich zones.
◉ Significance: Indicates thrombus formation in flowing blood (antemortem clot).
Feature
Arterial Thrombi
Venous Thrombi
Gross Appearance
  1. White and friable
  2. Occlusive
  1. Red and soft
  2. Occlusive
Microscopy
  1. Friable meshwork of platelets, fibrin, red cells, and degenerating leukocytes
  1. More enmeshed red cells due to sluggish venous circulation
▢ Endothelial Injury:
▢ Alterations in Normal Blood Flow:
▢ Hypercoagulability:
▢ Fate of the Thrombus:
Disseminated Intravascular Coagulation
Embolism
▢ Pulmonary Embolism:
▢ Systemic Thromboembolism:
▢ Fat and Marrow Embolism:
▢ Air Embolism:
▢ Amniotic Fluid Embolism:
Infarction
Feature
Red Infarct
White Infarct
Type of occlusion
Occurs with venous occlusion
Occurs with arterial occlusion
Tissue type
Occurs in loose tissues
Occurs in solid organs
Vascular supply
Occurs in tissues with dual circulation (e.g., lungs, intestine)
Occurs in tissues with end-arterial circulation (e.g., heart, kidney, spleen)
Additional factor
Occurs when flow is re-established to a site of previous arterial occlusion and necrosis
Occurs in tissues where density limits seepage of blood from adjoining capillaries
Shock
▢ Definition: Shock is defined as systemic hypoperfusion caused by reduction either in cardiac output or in the effective circulating blood volume.
▢ Types of shock:
▢ Pathogenesis of Septic Shock:
▢ Stages of Shock: