Pathology Basics
83 flashcards by MentisLibrary
How disease actually works at the level of the cell and the tissue: injury and adaptation, the necrosis types, the full inflammatory cascade, healing and repair, neoplasia, and the hemodynamic disorders behind shock and thrombosis.
- What is pathology?
- The study of disease, covering its causes, mechanisms, structural changes and functional consequences
- What is the difference between etiology and pathogenesis?
- Etiology is the cause of a disease, while pathogenesis is the sequence of events by which that cause produces disease
- What are the main causes of cell injury?
- Hypoxia and ischemia, physical and chemical agents, infection, immune reactions, genetic defects, nutritional imbalance and aging
- What is the difference between hypoxia and ischemia?
- Hypoxia is oxygen deficiency, while ischemia is reduced blood flow, which removes oxygen and nutrients and lets waste accumulate
- What are the hallmarks of reversible cell injury?
- Cellular swelling and fatty change, both of which resolve if the insult is removed
- What marks the point of no return in cell injury?
- Severe mitochondrial damage and membrane rupture, especially of lysosomes, releasing enzymes that digest the cell
- How do free radicals injure cells?
- They strip electrons from lipids, proteins and DNA, propagating chain reactions of oxidative damage
- What is coagulative necrosis?
- Necrosis in which tissue architecture is preserved for days because denatured enzymes cannot digest the dead cells
- What is liquefactive necrosis?
- Necrosis in which enzymatic digestion turns the dead tissue into a viscous liquid
- What is caseous necrosis?
- A cheese like, crumbly white necrosis in which tissue architecture is completely obliterated
- What is fat necrosis?
- Destruction of adipose tissue in which released fatty acids bind calcium and form chalky white deposits
- What is fibrinoid necrosis?
- Necrosis of vessel walls in which immune complexes and fibrin deposit and produce a bright pink smudge on microscopy
- What is gangrenous necrosis?
- A clinical term for necrosis of a limb or organ, dry when purely ischemic and wet when bacterial infection is superimposed
- How does apoptosis differ from necrosis?
- Apoptosis is programmed, energy dependent single cell death without inflammation, while necrosis is uncontrolled and provokes inflammation
- What are the two pathways to apoptosis?
- The intrinsic mitochondrial pathway and the extrinsic death receptor pathway, which converge on caspase activation
- What is atrophy?
- A decrease in the size and number of cells, shrinking the tissue or organ
- What is hypertrophy?
- An increase in cell size, and therefore organ size, without an increase in cell number
- What is hyperplasia?
- An increase in the number of cells in a tissue
- What is metaplasia?
- The reversible replacement of one differentiated cell type by another that better tolerates the stress
- What is dysplasia?
- Disordered growth with loss of uniformity and architectural orientation, a precancerous change
- What is carcinoma in situ?
- Full thickness dysplasia of an epithelium that has not yet broken through the basement membrane
- What is anaplasia?
- Complete loss of differentiation, the hallmark of aggressive malignancy
- What are the five cardinal signs of acute inflammation?
- Redness, heat, swelling, pain and loss of function
- What vascular changes occur in acute inflammation?
- Brief vasoconstriction, then vasodilation with increased blood flow, then increased vascular permeability and slowing of flow
- What are the steps of leukocyte recruitment in inflammation?
- Margination, rolling, firm adhesion, transmigration through the vessel wall, and chemotaxis to the injury
- Which cell type dominates the first 24 hours of acute inflammation?
- The neutrophil
- What are the main actions of histamine in inflammation?
- Vasodilation and increased vascular permeability, plus bronchoconstriction
- What do prostaglandins contribute to inflammation?
- Vasodilation, increased pain sensitivity and fever
- What do leukotrienes contribute to inflammation?
- Bronchoconstriction, increased vascular permeability and neutrophil chemotaxis
- What does bradykinin do?
- Causes vasodilation, increased permeability and, distinctively, pain