Cellular Injury (CHP 3) Flashcards
Define common cellular adaptations based on general etiologies and cellular manifestations. Explain common etiologies of cellular injury. Summarize the effect hypoxia has on cell and tissue function. Compare and contrast cell death associated with necrosis vs apoptosis.
what are the 2 kinds of cellular adaptations?
pathologic, physiologic
What defines common cellular adaptations?
Adaptations are based on general etiologies and cellular manifestations.
What makes an adaptation pathologic?
Change in cell behavior due to an abnormal stimulus leading to impaired function or increased risk of disease.
What is atrophy?
Decrease in cell size due to decreased workload or adverse environment.
What are the common causes of atrophy? (5)
- Disuse atrophy (casting, bedrest)
- Denervation (paralyzed)
- Lack of hormonal stimulation (meopause)
- Malnutrition
- Cellular hypoxia/ischemia.
What is hypertrophy?
Increase in cell size and tissue mass.
What initiates hypertrophy?
- Increased workload
- ATP depletion
- Stretch of muscle fibers
- Hormonal factors.
What characterizes pathologic hypertrophy?
It occurs as a result of disease conditions.
What is hyperplasia?
An increase in the NUMBER of cells in an organ/tissue.
What are examples of physiologic hyperplasia?
- Hormonal: breast and uterine enlargement from estrogen
- Compensatory: regeneration of liver after partial removal.
What is metaplasia?
Reversible change where one adult cell type is replaced by another adult cell type.
What is dysplasia?
Deranged cell growth characterized by variation in size, shape, and organization.
What is accumulation in cellular pathology?
Build up of substances that cells cannot immediately use or eliminate.
What are common examples of substances that can accumulate in cells?
- Lipids
- Proteins
- Carbohydrates
- Melanin
- Bilirubin.
What is dystrophic calcification?
Calcification that occurs in injured tissues.
What causes metastatic calcification?
Increased serum calcium levels (hypercalcemia).
What are examples of physical agents causing cell injury?
- Mechanical forces
- Extreme temperature
- Electrical forces
What types of injuries can extreme temperature cause?
- Low intensity heat: partial thickness burns
- Intense heat: coagulation of BVs
- Cold (frostbite): hypoxic tissue injury.
- heatstroke
- blood viscosity
What are the effects of chemical injury on cells?
Injure membrane, block enzyme pathways, coagulate proteins, disrupt osmotic and ionic balance, disrupt metabolism.
What are common sources of lead toxicity?
- Occupational exposure
- Chipping paint
- Root vegetables
- Dust and soil.
- Lead water pipes.
What is a free radical?
A highly reactive molecule with an unpaired electron.
What is the effect of hypoxia on cells?
Decreased production of ATP (Na/K pump failure)
anaerobic metabolism
accumulation of lactate
fall in pH
cell death.
What are the primary effects of hypoxia on tissue function?
Lack of O2 leads to decreased ATP production and altered metabolism.
Fill in the blank: An increase in cell size due to increased workload is called _______.
Hypertrophy.
True or False: Metaplasia is a reversible change in cell type.
True.
What is hypoxia?
Low levels of oxygen
Hypoxia can be caused by inadequate O2 in the air, respiratory disease, ischemia, anemia, edema, or an inability of cells to use O2.
What are the example causes of hypoxia?
- Inadequate O2 in air
- Respiratory disease
- Ischemia (vasoconstriction or obstruction)
- Anemia
- Edema
- Inability of cells to use O2
What is the primary effect of hypoxia on cell metabolism?
Decreased production of ATP (energy)
What happens to metabolism during hypoxia?
Metabolism becomes anaerobic or slows/stops
What accumulates in tissues during hypoxia?
Lactate (lactic acid)
What happens to pH levels in tissues during hypoxia?
pH falls
What are the signs of cell death due to hypoxia?
- Chromatin clumping
- Cell shrinkage
What is the role of the Na/K ATPase pump in hypoxia?
Failure of Na/K ATPase pump leads to decreased intracellular potassium levels
What occurs to intracellular sodium and water during hypoxia?
Intracellular sodium and water accumulate in the cell, causing swelling and damage
What changes occur to the cell membrane during hypoxia?
Cell membrane becomes more permeable
What is the difference between necrosis and apoptosis?
- Necrosis: cell death in an organ or tissue that is still part of a living person
- Apoptosis: Programmed cell death, highly selective
What characterizes reversible cell injury?
- Impairs cell function
- No death
- Cellular swelling
- Fatty change
What is an example of irreversible cell injury?
Apoptosis
What are the steps of apoptosis?
- Shrinking and condensation of nucleus and cytoplasm
- Chromatin aggregates at nuclear envelope
- DNA fragmentation
- Formation of multiple apoptotic bodies
What are examples of normal physiological apoptosis?
- Reduction of breast tissue after breastfeeding
- Separates webbed fingers during embryogenesis
What diseases are associated with pathological apoptosis?
- Cancer
- Neurodegenerative diseases (e.g., Alzheimer’s, Parkinson’s, ALS)
What is liquefactive necrosis?
Some cells die, but enzymes are not released (discharge and abscess)
What is coagulative necrosis?
Gray firm mass develops due to acidosis and denaturation of proteins (infarction = death)
What is caseous necrosis?
Dead cells persist indefinitely, commonly found in tuberculosis (granulomas)
What is gangrene?
A large mass of tissue undergoes necrosis
What are the key symptoms of dry gangrene?
- Tissue becomes dry and shrinks
- Skin wrinkles
- Color changes to dark brown or black
- Slow spread
What causes dry gangrene?
Interference with arterial blood supply without interference with venous return (EXTREMITIES)
What are the symptoms of wet gangrene?
- Cold
- Swollen
- Pulseless
- Moist
- Black and under tension
- Foul odor
- blebs/blisters
- RAPID
What is gas gangrene?
Bubbles of hydrogen sulfide gas form in muscle, can be fatal
What causes gas gangrene?
Infection of devitalized tissues by Clostridium bacteria (after trauma/dirt)
Define exogenous.
Developed and originated outside of the body
Define endogenous.
Growing within the body or developing from within the body
Define compensatory.
Reducing or offsetting the unpleasant effects of something
Define pathologic.
Involving or caused by a physical or mental disease
What is ischemia?
Reduced blood supply to a part of the body
What does denervation mean?
Loss of nerve supply to a specific area of the body
cells adapt by undergoing changes in: (3)
size (hypertrophy, atrophy)
number (hyperplasia)
form (metaplasia)
atrophy is common in… (4)
heart, skeletal muscle, sex organs, and brain
hypertrophy is common in … (2)
cardiac and skeletal muscle
what are the 2 kinds of pathologic hypertrophy and examples
adaptive hypertrophy (LVH)
compensatory hypertrophy (organ removal)
what tissue types is it common to see hyperplasia in?
(cells that can divide) epidermis, intestinal epithelium, glandular tissue
example of pathologic hyperplasia
increase in hormones or growth factors –> BPH, or endometriosis (++ estrogen)
hyperplasia may occur with _________
hypertrophy
what does metaplasia occur in response to?
chronic inflammation and irritation
____________: replaces cells original cells with cells that are more likely to survive
metaplasia
metaplasia is ___________ which is why it is non-cancerous
reversible (removal of stimulus)
changes in mucosal membranes lining the throat in response to smoking is an example of __________
metaplasia
where does dysplasia most commonly occur?
epithelium of the respiratory tract and uterine cervix
dysplasia is ________ (cancerous)
abnormal
dysplasia can be ____________, an example is the removal of a mole
reversible
what causes the accumulation of normal body substances?
production of substances happens at a greater rate thanthe use
what are 2 negative effects of cellular accumulations
scarring of organ tissue
insufficient ATP and hypoxia
abnormal tissue deposits of ______ salts –> _____ tissue area –> activated damaging _______ –> tissue ______ —> impaired _______
calcium
hardens
enzymes
damage
function
what is an example of dystrophic calcification?
atherosclerosis
what are 2 examples of metastatic calcification?
hyperparathyroidism
metastatic bone cancer
what are 3 examples of exogenous products?
lead poisoning
tattoo ink
polluted environment
why do exogenous products accumulate?
they aren’t broken down by the cell
abnormal endogenous products are results from ________ disorders that are result from _______ errors of ____________
genetic
inborn
metabolism
2 examples of endogenous product accumulations
Tay Sachs (fatty deposits in the brain)
Jaundice
physical agents cause _______ damage to tissues, such as a rupture, damaged _________, swelling
direct
membrane
3 types of chemical cell injury
drugs alcohol
lead
CO (binds with heme = less O2)
3 types of radiation injury
ionizing radiation (cancer)
UV radiation (sunburns)
nonionizing radiation (US, microwave)
radiation injuries rapidly _________ cells
dividing
injuries from biological agents: viruses, parasite, and bacteria are dangerous because (3)
they can replicate in the body
release toxins
impact ATP production
excess of nutrition (ex: fats) can lead to …
disease and it’s harder for O2 to get to tissues
cell can be _______ or _________
direct
indirect
what are the 3 mechanisms of cell injury?
free radical formation (oxidative stress –> changes in DNA –> damage)
hypoxia/ischemia or no ATP
impaired calcium homeostasis (intracellular Ca+ increases = damage)
ROS is an ______________ can be endogenous or exogenous (from _________)
O2 containing molecule
radiation
what are the 2 patterns of reversible cell injury?
cellular swelling
fatty change
cellular swelling:
1. __________ permeability
2. intracellular K+ ________
3. Na/H2O move _______ cell
4. swelling
increased
decreases
into
fatty change in cells is ________ (but reversible) because it means fat metabolism pathways are injured
severe
apoptosis eliminates cells that … (4)
worn out
produced in excess
developed improperly
genetic damage
necrosis interferes with cell ___________ and tissue _________
replacement
regeneration
what are granulomas?
small, localized clusters of WBCs in response to inflammation, infection, or foreign objects
what causes wet gangrene?
lack of venous emptying = infection risk
extremely or internal organ
systemic = severe
