Definitions for wk 4 Flashcards
Atrophy
Adaptive, generally reversible
Reduction in cell size
Example: Hepatocellular atrophy in starvation
Hypertrophy
Increased cell size
Example: Myocardial hypertrophy with stenotic heart valves
Adaptive, generally reversible
Abiotrophy
Degeneration of an organ/tissue after a period of normal development. Similar to atrophy
Hyperplasia
Increased number of cells, thus an increase in overall size
Adaptive, generally reversible
Example:
Goblet cell hyperplasia with chronic irritation
Metaplasia
Change from differentiated cell type into another mature differentiated cell type
Adaptive, potentially reversible, may reverse with removal of the irritant stimulus, however prolonged stimulation can lead to neoplasia
Example: Osseous metaplasia: transformation into bone with chronic irritation
Neoplasia
Uncontrolled proliferation of a clone of abnormal cells caused by acquired (can be inherited in some cases) alterations in the genome in of a progenitor
Dysplasia
Architectural or cellular disorder/absence of normal structure or differentiation
Adaptive, potentially reversible, may reverse with removal of the irritant stimulus, however prolonged stimulation can lead to neoplasia)
Example:
Squamous metaplasia and dysplasia in the trachea of smokers due to chronic irritation
Apoptosis
Programmed cell death
Necrosis
Uncontrolled cell death
Agenesis
Complete failure to develop
eg Unilateral renal agenesis
Hypoplasia
Failure to attain normal size
Cerebellum hypoplasia with intrauterine herpesvirus infection
Harmatoma
Overgrowth of abnormal tissue in a normal location.
Extreme form of dysplasia, NOT neoplastic, no mutations
Choristoma
An OVERgrowth of normal tissues in an abnormal location
Ectopic
Growth of normal tissue in an unusual/abnormal location
Oncogenesis
The complex process of the formation of neoplasia
