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USMLE
Cell Bio/Histo/Path -3
Question | Answer |
---|---|
Inflammation: Classic signs | -Rubor (redness) -Dolor (pain) -Calor (heat) -Tumor (Swelling) -Functio lassa (Loss of function) |
Characteristics of Inflammation: Fluid exudation | 1. Increased vascular permeability 2. Vasodilation 3. Endothelial injury |
Characteristics of Inflammation: Leukocyte activation | 1. Emigration 2. Chemotaxis 3. Phagocytosis and killing |
Characteristics of Inflammation: Fibrosis | 1. Fibroblast emigration and proliferation 2. Deposition of extracellular material |
Characteristics of Acute Inflammation | Mediated by: 1. Neutrophils 2. Eosinophils 3. Antibodies |
Characteristics of Chronic Inflammation | Mediated by mononuclear cells: -Characterized by persistant destruction and repair -Granulomas: nodular collections of macrophages and giant cells |
Characteristics of Inflammation: Resolution | 1. Restoration of normal structure 2. Granulation tissue 3. Abscess 4. Fistula 5. Scarring |
Granulation tissue: histologic characteristics | -highly vascularized -fibrotic |
Abscess: histologic characteristics | fibrosis surrounding pus |
Fistula: characteristics | abnormal communication |
Scarring: histologic characteristics | Collagen deposition resulting in altered structure and function |
Steps in leukocyte emigration | 1. Rolling 2. Tight binding 3. Diapedisis 4. Migration |
Leukocyte emigration step characteristics: Rolling | Binding between: -E-selectin on vascular endothelium -Sialyl-LewisX on the leukocyte |
Leukocyte emigration step characteristics: Tight binding | binding between: -ICAM-1 on vascular endothelium -LFA-1 on leukocyte |
Leukocyte emigration step characteristics: Diapedesis | leukocyte travels between endothelial cells and exits blood vessel |
Leukocyte emigration step characteristics: Migration | Leukocyte travels through interstitium to the site of injury or infection guided by chemotactic signals |
Chemotactic signals | 1. Bacterial products 2. Complement 3. Chemokines |
Free radical injury: Initiated by what? | 1. Radiation exposure 2. Metabolism of drugs (phase I) 3. Redox reactions 4. Nitric oxide 5. Transition metals 6. Leukocyte oxidative burst |
Free radical injury: Mechanism | -Membrane lipid peroxidation -Protein modification -DNA breakage |
Free radical injury: Stopped by what? | -Spontaneous decay -Antioxidants --Vitamin E --Vitamin A -Enzymes --Catalase --Superoxide dismutase --Glutathione peroxidase |
Major cause of injury after thrombolytic therapy | Free-radical production induced by reperfusion after anoxia |
Hyperplasia: definition | reversible increase in number of cells |
Metaplasia: definition | Reversible substitution of one cell type for another. |
Metaplasia: When found? | Often secondary to irritation and/or environmental exposure (eg squamous metaplasia in trachea and bronchi of smokers) |
Dysplasia: definition | Reversible abnormal growth with loss of cellular orientation, shape and size in comparison to normal tissue maturation |
Dysplasia: When found? | In paraneoplastic syndromes |
Anaplasia: definition | abnormal cells lacking differentiation, like primitive cells of same tissue. |
Anaplasia: When found? | Undifferentiated malignancies |
Neoplasia: Definition | A clonal proliferation of cells that is uncontrolled and excessive |
Difference between hyperplasia and dysplasia | Can occur together 1. hyperplasia - increase in number 2. dysplasia - abnormal proliferation of cells with loss of size, shape, and orientation |
Appearance of cancerous cells | -High nuclear/cytoplasmic ratio -Clumped chromatin |
How does carcinoma invade a basement membrane? | -Collagenases -Hydrolases |
Seed and soil theory of metastasis | Seed: Tumor embolus Soil: Target organ |
Tumor grade: definition | Degree of cellular differentiation based on histologic appearance of tumor |
Tumor stage: definition | Degree of localization/spread based on site and size of primary lesion, spread to regional lymph nodes, and presence of metastases |
Tumor grade vs stage: Quick characterization | grade: character of tumor itself stage: spread of tumor in a specific patient (Stage=Spread) |
Tumor grade vs stage: Which has more prognostic value? | Stage |
TNM staging system | Tumor size Node involvement Metastases |
Benign tumors of cell type: Blood cells | Does not exist. The malignant blood cells are automatically metastasizing. |
Benign tumors of cell type: Blood vessels | Hemangioma |
Benign tumors of cell type: Smooth muscle | Leiomyoma |
Benign tumors of cell type: Skeletal muscle | Rhabdomyoma |
Benign tumors of cell type: Bone | Osteoma |
Benign tumors of cell type: Fat | Lipoma |
Benign tumors of cell type: >1 cell type | Mature teratoma (women) |
Benign tumors of cell type: Epithelium | -Adenoma -Papilloma |
Malignant tumor of cell type: Epithelium | -Adenocarcinoma -Papillary carcinoma |
Malignant tumor of cell type: Blood cells | -Leukemia -Lymphoma |
Malignant tumor of cell type: Blood vessels | Angiosarcoma |
Malignant tumor of cell type: Smooth muscle | Leiomyosarcoma |
Malignant tumor of cell type: Skeletal muscle | Rhabdomyosarcoma |
Malignant tumor of cell type: Bone | Osteosarcoma |
Malignant tumor of cell type: Fat | Liposarcoma |
Malignant tumor of cell type: >1 cell type | Immature teratoma, Mature teratoma (men only) |