Pathology Flashcards
Definitions of pathology
1) Science that studies the structural, molecular and functional manifestations of disease and the mechanisms that cause disease 2) The structural and functional manifestations of disease 3) A disease (structural molecular and functional, just structural and functional, disease)
Things that pathologists do…
evaluate surgical, cytologic, hematologic and autosy specimens microbiology, immunology, coagulation and biochemical testing blood transfusion, apheresis, stem cell and donor services genetic testing and tissue typing
What is a disease?
Molecular, cellular, tissue, organ and organismic damage caused by an etiology and mediated by pathogenic mechanisms (disease = damage, of what? cell, tissue, organ caused? etiology, what else: pathogenic mechanisms)
How to name disease
caused by, then what happens ex. bacterial pneumonia (inflammatory process in lung) can also have molecular characterization ex. ER/PR/HER2 - invasive ductal carcinoma
Cause of a disease
Etiology (VINDICATE)
Mechanism of a disease
Pathogenesis
Etiology Mnemonic
Vascular Inflammatory Neoplastic Drug/toxin Infectious Congenital/genetic Autoimmune/immune Trauma/physical Endocrine/metabolic/nutritional
Diagnosis
name of disease
Pathogenesis
sequence of events that leads from the etiology to the manifestations of disease (sequence, etiology –> disease manifestations)
Symptom
Disease manifestation perceived and reported by pt
Sign
Manifestation of disease that can be identified by physical examination, lab tests, imaging studies and other methods
DD
A ranked list of the most likely diagnoses based on the signs and symptoms of disease in a given pt.
Reversible or not reversible subcellular changes? cellular swelling disaggregated ribosomes dialated vesicular ER aggregated cytoskeletal elements mitochondria swelling
Reversible
What are some cellular response to injury?
1) Hypertrophy 2) Hyperplasia 3) Atrophy 4) Metaplasia 5) Dysplasia 6) Neoplasia
Hypertrophy
increased SIZE in cells
note: results in increased organ or tissue size, cells are larger so nucleus is also larger
Hyperplasia
increased NUMBER in cells
Note: maturation is normal (see in picture the top of the cells still no nuclei), this picture has squamous epithelial cells
Atrophy
Causes of atropy
reduced size of cells or organs (opposite of hypertrophy)
Causes:
- reduced functional demand
- inadequate oxygen supply
- insufficient nutrients
- interrupted trophic signals
- persistent cell injury
- increased pressure
- chronic disease
Metaplasia
conversion of one differentiated cell type to another (that conversion was META!)
Dysplasia
disordered growth and maturation of the cellular components of a tissue (Dysplasia = DYSordered growth)
Dysplasia may be a precursor to malignant neoplasia.
Neoplasia
autonomous growth of cells that have escaped normal regulation of cell proliferation (neoplasia = NEO regulation yes proliferation)
Neoplasia - benign
neoplasmas that remain localized
Neoplasia - malignant
neoplasmas that spread to distant sites (cancer)
malignant neoplasms have less well differentiated cells that have larger nuclei that are pleomorphic, atypical, hyperchromatic and more often undergoing mitosis
Hydropic Degeneration
Irreversible change due to cell swelling
Apoptosis
Cell death caused by activation of internal molecular pathways leading to cell death (physiological tissue remodeling during embryonic development, renewal of epithelial layers)
Can be physiological (epithelial sloughing before renewal) or pathological (hep virus-induced hepatocyte loss)
Mitosis increases and apoptosis decreases.
Necrosis
Cell death caused by pathological lethal injury that often originates outside the cell (injury by hypoxia, inflammation, molecular toxin, burn etc)
Example of Apoptosis
Cell death caused by activation of internal molecular pathways
- tissue remodeling during embryonic development
- renewal of epithelial layers
- Pathway with TNFR receptor that Tumor necrosis factor binds and then triggers a molecular pathway that activates varioius caspaces
Picture: single weird cells amoung normal cells
How to determine cell death histologically?
Nuclear changes
Pyknosis
The nucleus becomes smaller and stains deeply basophilic because of chromatin clumping
(it is like an osis in there with all that staining and chromatin clumping)
Karyorrhexis
The pyknotic nucleus breaks up into many smaller fragments
(the nucleus breaks up into hexagons)
Karyolysis
The nucleus may be extruded from the cell or have progressive loss of chromatin staining resulting in the disappearance of the nucleus
(the nucleus is lysed)
Coagulative necrosis
Nuclei disappear (karyolysis) and cytoplasm becomes more homogeneous (and often more acidophilic) resulting in residual ghosts of cells with no nuclei.
(necrosis = cell death that originates outside cell, coagulative = cytoplasm homogenous, ghost cells!)
MI
Gross feature and histologic features
Gross features: localized discoloration
Histologic features: ischemic coagulative necrosis