1.9.18 Injury Patho

Question 1

3 things cells do when presented with a challenge

Answer 1

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

Question 2

Reversible Cell Injury: Hydropic

Answer 2

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

Question 3

Reversible: Intracellular accumulations

Answer 3

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)

Question 4

Cellular adaptations: responses to increases or decreases in demand

Answer 4

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

Question 5

Cellular adaptations: response to persistent injury

Answer 5

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)

Question 6

Irreversible cell injury: Necrosis

Answer 6

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

Question 7

Irreversible cell injury: Apoptosis

Answer 7

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

Question 8

Etiology of cell injury: Hypoxia and ischemia

Answer 8

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

Question 9

Reperfusion Injury and Reactive Oxygen species

Answer 9

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

Question 10

Cellular injuries: Nutritional and Chemical

Answer 10

Deficiencies (iron, vita D), excess (sodium)

Chemical: free radicals, heavy metals, toxic gases

Question 11

Cellular Injuries: physical

Answer 11

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

Question 12

Cellular injuries: infectious

Answer 12

bacteria: endo and exo
virus
indirect immunology