PP1 - 9/11 Ch4 Cell Injury, Aging, Death

2 types of reversible cell injury

hydropic swelling

intracellular accumulations

hydropic swelling

malfunction of sodium potassium pump -> accumulation of salt & mainly water

intracellular accumulations

Excess of accumulation of substances in cells

types of substances accumulated in intracellular accumulations (3)

normal

abnormal

pigment & particles

5 types of cellular adaptions

atrophy

hypertrophy

hyperplasia

metaplasia

dysplasia

atrophy

dec in cell size

atrophy causes (5)

lack of muscle use (cast, bedridden)

denervation (loss of nerve supply)

ischemia (interruption of blood flow to cells)

nutrient starvation

persistent cell injury

hypertrophy

inc in cell size

hypertrophy cause

consistent muscle usage (inc in physiological demands)

hyperplasia

inc in cell #

hyperplasia causes (2)

inc in persistent physiological demands

persistent cell injury (calus)

metaplasia

conversion of 1 cell type to another

metaplasia cause

persistent cell injury (calus)

dysplasia

disorderly growth

dysplasia cause

adaptive effort thats gone astray (can lead to a lesion ->cancer)

types of irreversible cell injury (3)

necrosis

gangrene

apoptosis

necrosis

Consequence of ischemia/toxic injury

necrosis 3 characteristics

cell rupture

spilling of contents into extracellular fluid

inflammation

4 types of necrosis

coagulative

liquefactive

fat necrosis

caseous

coagulative necrosis (2)

begins with ischemia

ends with degradation

liquefactive necrosis (4)

occurs w/dissolution of dead cells

liquification of lysosomal enzymes

formation of abscess/cyst from dissolved dead tissue

from bacterial infection (localized collection of WBC)

fat necrosis (3)

death of adipose tissue

result of trauma or pancreatitis

appears as a chalky white area of tissue

caseous necrosis (2)

characteristic of lung dmg from TB

resembles clumpy cheese

Gangrene (2)

cell death in large area of tissue

results from interruption of blood supply to a particular body part

3 types of gangrene

dry

wet

gas

dry gangrene (2)

blackened, dry, wrinkled tissue

seperated by line demarcation from healthy tissue

wet gangrene (4)

form of liquefactive necrosis

typically found in internal organs

cold, black, foul smell

can be fatal

gas gangrene (3)

formation of gas bubbles in dmged tissue

result of infection from necrotic tissue by anaerobic bacteria

can be fatal

Apoptosis function (2)

responds to injury that doesnt directly kill cell

activate a cellular death pathway if cells are no longer needed (cellular suicide)

Apoptosis characteristics (4)

no inflammation

not always pathological;dev based on need for tissue remodeling

dont rupture; usually ingested by neighboring cells

tissue hypoxia etiology

ischemia (lack of blood flow)

ischemia (4)

disruption of oxygen

allows metabolic waste accumulation

reperfusion injury (cell dmg after blood supply is restored)

most common cell injury

ischemia-reperfusion injury process (3)

Ca overload

free radicals formation

subsequent inflammation

types of cell injury etiologies

deficiencies

excesses

infections/immunologic inj

chemical inj

physical/mechanical inj

deficiencies as etiology of cell injury

fats, carbs, proteins, vitamins, minerals (some cell types more susceptible than others)

excesses as etiology of cell injury

nutritonal excesses (inc BMI)

BMI numbers of concern (2)

>25 kg/m2: health risk (overweight)

>30 kg/m2: obesity

infectious/immunologic injury (3)

bacteria

viruses

immune response

bacteria as etiology of cell injury

damage cells from outside

virus as etiology of cell injury

enter a cell to dmg from inside

immune response as etiology of cell injury

may be more dmging that the direct effect of infectious agent (potential added indirect inj due to already compromised immune system)

chemical injury as etiology of cell injury

toxic chemicals/poisons (directly & indirectly)

direct chemical injury as etiology of cell injury

too much tylenol -> liver damage

indirect chemical injury as etiology of cell injury

metabolized into reactive chemicals (bad reactions)

physical & mechanical inj (5)

temperature

atmospheric pressure

mechanical deformation

electricity

radiation

temperature (2) as etiology of cell injury

extreme heat - burns

extreme cold - hypothermic inj (frostbite)

atmospheric pressure (3) as etiology of cell injury

high altitude

deep sea diving

explosions

mechanical deformation as etiology of cell injury

mild abrasion - severe laceration & trauma (punched, falls down)

electricity as etiology of cell injury (3)

body acts as electrical conduct

disruption of neural & cardiac impulses

hyperthermic destruction (burns & extreme heat)

radiation as etiology of cell injury (2 effects)

genetic damage

acute cell destruction (dmg based on rate of proliferation [rapid inc in cell #])