1.9.18 Injury Patho Flashcards Preview

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Flashcards in 1.9.18 Injury Patho Deck (12):
1

3 things cells do when presented with a challenge

Withstand and return to normal (Reversible: hydropic, cellular accumulations)
Adapt (Generally reversible: atrophy, hypertrophy, hyperplasia, metaplasia, dysplasia)
Die (Irreversible: necrosis, apoptosis)

2

Reversible Cell Injury: Hydropic

Accumulation of water
1st manifestation
results from malfunction of NA-K pumps (NA in cell, water follows)
generalized swelling in cells
megaly: increase size and weight

3

Reversible: Intracellular accumulations

1) Excessive amounts of normal intracellular subs (glucose in diabetes)
2) Accumulation of abnormal subs produced by cells bc issues (excessive broken down protein)
3) accumulation of pigments and particles that cell is unable to degrade (hyperbelirubin)

4

Cellular adaptations: responses to increases or decreases in demand

1) Atrophy: cells shrink and reduce diff. fxn (due to disuse, wants to decrease energy used-protective)
2) Hypertrophy: increased cell size accompanied by augmented fxnal capacity (pregnancy: uterus, breasts)
3) Hyperplasia: increase in number of cells by mitotic division: usually goes hand in hand with hypertrophy

5

Cellular adaptations: response to persistent injury

1) Metaplasia: replacement of one differentiated cell type with another (smokers: brochial mucosa changes cell type)
2) Dysplasia: Disorganized appearance of cells because of abnormal variations in size, shape and arrangement (cervix tissue to STI)

6

Irreversible cell injury: Necrosis

toxic or ischemia injury; External injury
Cell RUPTUREs:intracellular contents spill out>inflammation
Disruption in cell membrane
Monitor "spill out" of cells for heart attack

7

Irreversible cell injury: Apoptosis

Can be natural or abnormal cell signaling
membrane does NOT rupture: no swelling/inflammation
phagocytic cells clean up

8

Etiology of cell injury: Hypoxia and ischemia

Hypoxia: poor O2; Ischemia: interruption of blood flow
plasma, mitochondrial and lysosomal membranes, damaged: cell death
MECH: decreased ATP and production, ATP pumps fail; Na accumulates, brings H2O into cell; Excess Ca mitochondria, glycogen stores depleted, lactate produced, ph falls

9

Reperfusion Injury and Reactive Oxygen species

1) calcium overload: can cause apoptosis
2) formation of reactive oxygen molecules:
3) Inflammation

10

Cellular injuries: Nutritional and Chemical

Deficiencies (iron, vita D), excess (sodium)
Chemical: free radicals, heavy metals, toxic gases

11

Cellular Injuries: physical

Physical and mechanical: temp extremes, abrupt changes in atmospheric pressure, abrasion, electrical, radiation

12

Cellular injuries: infectious

bacteria: endo and exo
virus
indirect immunology