Principles Of Pathology Flashcards
Major definitions of pathology (3)
- The science that studies the structural, molecular, and functional manifestations of a disease, and the mechanisms that cause disease. 2. The structural and functional manifestations of a disease. 3. A disease.
What are the targets for prevention and treatment of a disease?
Etiology (Cause) and Pathogenesis (Mechanisms of disease)
What is a disease?
Molecular, cellular, tissue, organ and organismic damage caused by an etiology and mediated by pathogenic mechanisms
What is a diagnosis?
The name of a disease
What is an etiology?
The cause of a disease
Etiology Mnemonic
VINDICATE: Vascular Inflammatory Neoplastic Drug/toxin Infectious Congenital/genetic Autoimmune/immune Traumatic/physical Endocrine/metabolic/nutritional
What is pathogenesis?
The sequence of events that leads from the etiology to the manifestations of disease
What is a symptom?
Disease manifestation perceived and reported by the patient
What is a sign?
Manifestation of disease that can be identified by physical examination, laboratory tests, imaging studies, and other methods.
What is a differential diagnosis?
A ranked list of the most likely diagnoses based on the signs and symptoms of disease in a given patient.
Subcellular changes in reversibly injured cells
What is hypertrophy?
Increased size of cells
Example: cardiomyocytes
What is Hyperplasia?
Example: epidermis (normal/psoriasis)
Non-neoplastic increase in number of cells (in organ or tissue)
What is Atrophy?
Example: frontal lobe; thinned gyri, widened sulci
Reduced size of cells or organs
Etiologies of Atrophy (7)
- Reduced Functional Demand (e.g. skeletal muscle atrophy caused by denervation)
- Inadequate Oxygen Supply (e.g. kidney atrophy caused by renal artery stenosis)
- Insufficient Nutrients (e.g. skeletal muscle and fat atrophy caused by starvation)
- Interrupted Trophic Signals (e.g. endometrial atrophy after menopause)
- Persistent Cell Injury (e.g. gastric mucosal atrophy caused by chronic gastritis)
- Increased Pressure (e.g. localized skin atrophy caused by prolonged bed rest)
- Chronic Disease (e.g. cachexia caused by chronic disease)
What is Metaplasia?
Conversion of one differentialed cell type to another
Example: endocervix; squamous metaplasia/normal colomnar epithelium
What is Dysplasia?
Disordered growth and maturation of the cellular components of a tissue; may be a precursor to malignant neoplasia
example: dysplastic epithelium of uterine cervix; lacks normal polarity & large hyperchormatic nuclei (normal left, dysplastic right)
What is Neoplasia?
The autonomous growth of cells that have escaped normal regulation of cell proliferation.
Localized = benign
Metastasize/capable of = malignant
Examples: benign = thyroid follicular adenoma; malignant = colonic adenocarcinoma, metastatic to liver
Uterus with multiple leiomyomas
Hydropic degeneration
abnormal swelling because of increased water within organelles
Adrenal Neoplasia
Benign adrenal adenoma
What are the two major pathways to cell death?
Apoptosis: cell death caused by activation of internal molecular pathways leading to cell death
AND
Necrosis: cell death caused by pathological lethal injury that often originates outside the cell
Histological nuclear changes demonstrated by cell death (3)
Pyknosis: The nucleus becomes smaller and stains deeply basophilic because of chromatin clumping.
Karyorrhexis: The pyknotic nucleus breaks up into many smaller fragments.
Karyolysis: The nucleus may be extruded from the cell or have progressive loss of chromatin staining resulting in the disappearance of the nucleus.
Coagulative Necrosis
Nuclei disappear (karyolysis) and cytoplasm becomes more homogeneous (and often more acidophilic) resulting in residual ghosts of cells with no nuclei
Gross vs. Histological features with MI
Liquifactive Necrosis
Rapid dissolution of cells that liquefies necrotic tissue.
Often caused by intense, localized infiltration of neutrophils at sites of severe acute inflammation
Localized acute inflammation with liquifactive necrosis is called an abscess
Caseous Necrosis
Necrosis caused by tuberculosis; marginal zone of aggregated macrophages & central zone of necrosis containing amorphous debris derived from necrotic host/mycobacterial cells.