Cellular Adaptations Flashcards
major adaptive responses
✓ atrophy
✓ hypertrophy
✓ hyperplasia
✓ aplasia
✓ hypoplasia
✓ metaplasia
✓ dysplasia
whereby a tissue or organ undergoes a reduction in mass (size), due to a decrease in the size and/or number of cells
adaptive response
decrease in the amount of a tissue or organ after normal growth has been attained
atrophy
organs are increased in size due to an increase in cell size without cellular proliferation
hypertrophy
increase in organ size or tissue mass caused by an increase in the number of constituent cells
hyperplasia
two main types of reversible cell injury are recognized
cellular swelling and fatty change
the most common and most important response to cellular injuries of all types
cellular swelling
cellular injuries of all types including;
✓ mechanical
✓ anoxic
✓ toxic
✓ lipid peroxidation
✓ viral
✓ bacterial
✓ immune mechanisms
as the process continues many vacuoles or variable size appear in the cytoplasm called?
hydropic or vacuolar degeneration
when severe (esp viral infected cells) called?
ballooning degeneration
a sick cell. a reversible form of injury. an adaptive change that may progress to cell death (necrosis)
degeneration
occurs in various forms of injury. see abnormal accumulation of lipids within the cell. many in cells dependant on fat metabolism
fatty change
fatty acids can also be synthesized from?
acetate
lipid metabolism and storage in liver
✓ lipids enter hepatocytes as free fatty acids
✓ lipids are metabolized by hepatocytes
✓ lipids are exported from hepatocyte
refers to the rapid death of a limited portion of an organism and is considered to be the final stage in irreversible degeneration
necrosis
is the term used for the entire process of degeneration and death of cella
necrobiosis
Gross indicators/characteristics of necrosis
✓ loss of color or paleness of the tissue
✓ loss of strength of the tissue
✓ definite zone of demarcation
✓ location or pattern of the lesion
the morphologic appearance is due to 2 concurrent processes;
✓ denaturation of proteins
✓ enzymatic digestion of the cell
also often used to describe the changes that occur in all of the cells after an animal has died
autolysis
most common manifestation of cell death
coagulation necrosis
predominates over enzymatic digestion
protein denaturation
may result from acute deprivation of blood supply
coagulation
3 patterns of nuclear changes
✓ karyolysis
✓ pyknosis
✓ karyorrhexis
dissolution/fading of the nucleus
karyolysis
shrunken and densely basophilic (also seen in apoptosis)
pyknosis
nuclear fragmentation
karyorrhexis
types of necrosis
✓ coagulation necrosis
✓ liquefactive necrosis
✓ caseous necrosis
✓ gangrenous necrosis
✓ fat necrosis
✓ infarction (ischemic necrosis)
✓ Zenker’s necrosis
occurs when enzymatic digestion of necrotic cells predominates over protein denaturation
liquefactive necrosis
typical lesion seen with specific bacterial diseases. common in birds since heterophils don’t have the potent hydrodrolytic enzymes to liquefy cells
caseous necrosis
necrosis (usually ischemic) of extremities. occurs when saprophytic grow in necrotic tissue
gangrenous necrosis
two types of gangrene
✓ dry gangrene
✓ wet gangrene
occurs in necrotized portion of the skin with moisture loss due to evaporation and drainage and presence of saprophytic bacteria
dry gangrene
when the coagulative necrosis of dry gangrene is modified by the liquefactive action of invading saprophytic. or moist gangrene, color is usually black
wet gangrene
type of necrosis distinguished by its location within body fat stores, esp abdominal or subcutaneous fat
fat necrosis
a form of coagulative necrosis resulting from a sudden deprivation of blood supply
infarct
type coagulative necrosis in striated muscles characterized by loss of striations following necrosis
Zenker’s necrosis
is a shallow area of necrosis confined to epidermis that heals without scarring
erosion
is an excavation of a surface produced by necrosis and sloughing of the necrotic debris and implies involvement of the tissue below the surface layer.
ulcer
is a piece of necrotic tissue in the process of separation from viable tissue and implies a process of shedding when used with reference to a surface
slough
an area of liquefactive necrosis of the nervous tissue. literally means softening
malacia
an isolated necrotic mass
sequestrum
favorable outcome
✓ organization
✓ petrifaction
✓ ossification
✓ aseptic autolysis
death of single cells as a result of activation of a genetically programmed “suicide” pathway
apoptosis
