cell injury degeneration and death Flashcards
degeneration is …… while cell death is …..
reversible….irreversible
classifications of reverisble cell injurt?
changes associated with Disturbed
-water metabolism
-Disturbed fat metabolism
-Disturbed Mucopolysaccharides
iHyaline change
degrees of water accumaltion in a cell ad their name
mild → cloudy swelling
moderate → vacuolar degeneration
severe → hydropic degeneration
mild accumaltion of water is called?
cloudy swelling
moderate accumulation of water in a cell is called?
vacuolar degeneration
whats the name of severe accumulation of water in the cell n
hydropic degeneration
what organs are affected during disturbed water metabolism?
specialized cells of parenchymatous organs (kidney, liver , heart)
pathogenesis of cloudy swelling?
mitochondrial swelling → fragmentation →
low ATP production → failure of Na pump→ retention of Na and
water inside cell
pathogenesis of hydropic degenration
inc cell membrane permeability thus influx of water
fatty change=steatosis which is abnormal accumulation of fat inside cells… what are its causes?
1.Bacterial toxins (diphtheria)
2.Chemical toxins
3.Malnutrition and chronic alcoholism
organs affected from steatosis?
liver,kidney heart
gross pic of fatty change in the organs?
inc size of organ
pale yellow color
soft
microscopic shape of organs affected from steatosis/fatty change
fat globules distend the cell (1)→ unite to a single large one
pushing the nucleus “signet ring cell”(2
what is signet ring cell?
it is the result of fusion of accumulated fat globules then pushing the nucleus
what is lipomatosis?
Lipomatosis is Localized accumulation of
fat not necessarily
associated with marked
obesity
diff between obesity and lipomatosis?
-Obesity: Excessive accumulation of
fats in normal sites due to
over nourishment along
with sedentary life or to
!disturbance of endocrine
glands.!
-Lipomatosis: Localized accumulation of
fat not necessarily
associated with marked
obesity
mention the changes associated with mucopolysaccharide metabolism
-Mucoid degeneration: accumulated mucin
within epithelial cell
-Myxomatous degeneration: accumulated MPS
in connective tissue
what’s hyaline change (degeneration)
hyaline material is eosinophilic, homogenous and structureless.
can deposit intra or extra cellular within CT depending on the disease process
whats the diff between necrosis and apoptosis?
-Necrosis :Local death of a group of cells inside the living tissue
-Apoptosis: Regulated, programmed cell death
cell size of cell during nEcrosis?
Enlarges
cell size during apoptosis
Shrinked
what happens to the nucleus in both necrosis and apoptosis?
necrosis: Pyknosis=nuclear contestation , karyorrhexis: nuclear fragmentation, karyolysis: dissolution of nucleas <:
apoptosis: nuclear fragmentation
cell membrane during necrosis and apoptosis?
necrosis: disruoted
apoptosis: intact
necrosis or apoptosis is present with adjacent inflamamtion?
Necrosis
gross pic of necrosis?
pale tissue with peripheral hyperaemia
which is due to pathologic reasons only… necrosis or apoptosis?
necrosis
types of necrosis?
- Coagulative necrosis
- Liquefactive necrosis
- Caseous necrosis
- Fat necrosis
- Fibrinoid necrosis
- Gangrenous necrosis
where does coagulative necrosis occur?
in hypoxic cell death (anywhere except for the brain)
which type of necrosis the cell architecture is still intact?
coagulative necrosis
caseous necrosis
TB
gross description of tb/caseous necrosis
yellow-white, friable , necrotic tissue
microscopic description of caseous necrosis
-no cellular outline
-necrotic area is surrounded by specific inflammatory reaction
whats fat necrosis?
A focal area of fat destruction
mechanism of fat necrosis
In acute pancreatitis: release of pancreatic
enzymes into pancreatic substance
→ liquefy membranes of fat cells
→release of fatty acids→ fatty acids + Ca++
→ chalky- white areas
GANGRENE def
Massive necrosis followed by putrefaction
causes of gangrene?
A. Arterial occlusion. examples:
Thrombosis
Embolism
Strangulation
Vascular compression
B.Venous occlusion
C.Bacterial infection “infective gangrene”/putrefaction.. example: Saprophytes “bacteria”
causitive agent of putrefaction and how?
SAPROPHYTES
act on dead tissues
Dead tissues
hydrogen sulphide
Hydrogen sulphide + Iron “from HB” → Iron sulphide “black”
What is the cause of the black coloration of the
gangrenous tissue?
Saprophytes “bacteria” → act on dead tissues
Dead tissues
hydrogen sulphide
Hydrogen sulphide + Iron “from HB” → Iron sulphide “black”
senile gangrene is a type of dry gangrine
which can occur in limbs especially feet… why is that?
most distant from heart”
senile gangrene is a type of dry gangrine
which can occur with old age…. why?
atheroscelrosis
why dry gangrenes are dry?
arteries are impeded , veins are patent (مفتوحة عادي) therefore normal drainage of fluids
as well as surface evaporation in limbs leads to poor tissue fluids
tight shoes can lead to what?
its a slight trauma that can cause dry gangrene
whats line of demarcation
its a line that can be seen by naked eyes that between gangrenous and healthy tissue
A red zone of acute inflammation
whats line of separation?
line cant be seen by naked eyes which is about : A groove in the area of inflammation →
deepens → dead part separates from the healthy tissue
why is the stump is conical??
Because gangrene spreads higher up in
skin & SC tissue (less arterial blood supply) than muscle and
bones.
how is moist gangrene 7slt?
Sudden occlusion of artery and vein so No evaporation of fluid → rapid putrefaction→ toxemia
site of moist gangrene?
-internal organs (intestine)
-extremities in severe crush wounds.
what characterizes moist gangrene?
Poor line of demarcation
* Absent line of separation
* Rapid spread of gangren
what is diabetic foot?
wet gangrene affecting the foot of the diabetic folks
why diabetic gangrene occur?
Starts dry in big toes→ rapidly moist due to 2ry infection Severe toxemia
so what happens:
premature atherosclerosis→ elevated tissue sugar level → ↓ immunity
→ sensory loss → slight injuries are not felt
whats bed pressure sore?
wet gangrene :Bed ridden→ thrombosis of vessels → tissue necrosis → ulcers over
bony prominences (vertebrae sites)
why in the intestinal gangrene (wet gangrene) the Gangrene extends very rapidly
Because intestine is rich in
tissue fluids& saprophytes
examples on infective gangrene?
-Lung gangrene on top of lung abscess
-Cancrum oris cheeks of debilitated children “bacteria:
Treponema vincenti” Severe toxemia
whats cancrum oris / noma?
necrotizing ulcerative
Stomatitis.
involved bacteria in gas gangrene?
clostridia family
involved bacteria in cancrum oris (infective gangrene)?
treponema vincenti
bacteria involoved in putrefaction in wet gangrene?
saprophytes
Predisposing factors of gas gangrene om ree7a zeft?) co2 and H2S
ompound fractures, penetrating injury and
agricultural acciden
just read ana already t3bt
Agricultural accidents→ deep wounds contaminated by manure
containing anaerobic spores → vascular damage→ local ischemia →
germination of spores
anareboic spores so it will go to SC
gross description of gas gangrene?
area is swollen, oedematous with a foul smelling discharge
microscopic description of gas gangrene?
Connective tissue and muscles are
oedematous and necrotic with gas
formation.
Non- specific inflammatory
reaction
The causative organism may be
seen in the wound (gram stain)
OSPE: mention the causes of necrosis
loss of blood supply
trauma
toxins
physical and chemical agent
pathopgenesis of diabetic gangrene?
-diabetes… atherosclerosis…thrombosis
-sensory loss so slight injuries are not felt
- inc sugar level in blood so low immunity
it starts in the big toe bc rapidly moist infective gangrene due to 2ndry infection, therefore the areas are edematous and moist
-severe toxiemia
