Cell Growth,injury, Death Flashcards
(22 cards)
What is pathology?
The study of structural and functional changes in cells,tissues and organs that underlie disease
State different ways cells can grow
Multiplicative growth
Auxetic growth - grow in size
Accretionary growth - shrink in size
Combined pattern of growth
List types of cells
Liable cells - always regenerating e.g hemopoietic or epithelial cells
Stable cells- stops at G0 and renters cell cycle after injury e.g hepatocytes renal tubules
Permanent cells- once dead cannot be replaced skeletal/cardiac muscle ,neurons
List 5 types of cellular adaptation
Hyperplasia Hypertrophy Atrophy Hypoplasia Metaplasia
Define hyperplasia and state two causes for adaptation
Increase in number if cells (normal)
Increase growth factor
Physiological - eg hormonal (puberty growth of breast) compensatory ( multiplication of liver if cut)
Pathologic - abnormal hormones (benign prostate hyperplasia), viral (warts) ,
What is hypertrophy and state causes
And mechanism
Increase in size of the cell
Causes - high demand , hormones, growth factors
Physiologic - increase in skeletal/cardiac muscle size (does not multiply)
Pathologic - hypertension( cardiac muscle increase)
Mechanism - GF stimulated,vasoactive agents
What is atrophy
Causes
Mechanism
(Reversible) Shrinkage of size of the cell due to loss of cell substance without cell actually dying
Causes- physiological- thymus and uterus(with age)
Disuse - loss of type 11 muscles
Loss of innervation- loss of blood supple, nutrition
What is the mechanism of atrophy
Mechanism- decreased protein synthesis and increase protein degeneration- ubiquitin protease pathway
Autophagy
Reduced metabolic activity
What is Metaplasia?
State types
Give examples
A reversible change in which one adult cell type replaced by another cell type
Types: epithelial & mesenchymal
Epithelial - squamous and columnar
Eg. Respiratory epithelial(smoke causes columnar with squamous which cannot have cilia), Barrett’s esophagus( acid reflux replaces squamous with columnar which is less strong)
List some causes of cell injury
Hypoxia - oxygen deprivation is very common cause of cell injury and death Physical agents (temperature) Chemical agents and drugs Infectious agents Immunologic reactions Genetic derangement Nutritional imbalance
Cellular injury
Loss of oxygen causes these cellular injury
ATP depletion
Oxygen derive free radicals
Loss of calcium homeostatasis
Defects in membrane permeability( electrolyte imbalance)
Irreversible mitochondrial damage(less ATP)
State how cell injury can lead to ER swelling, cellular swelling, loss of microbiology and blend
Blockage causes decreased oxygen
Decrease oxygen leads do decrease oxidative phosphorylation
Dec. OP causes dec. in Na pumps
Dec. Na causes higher influx of Na, Ca and H2O
Describe how cell injury can lead to clumping of nuclear chromatins
Dec. OP
Dec. ATP
Inc. anaerobic glycolysis
Dec. glycogen , inc. lactic acid.. dec. ph
How does cell injury affect lipid deposition
Dec OF
Dec ATP
Detachment of ribosomes
Dec protein syntheses
State the types of cell injury
Normal homeostasis - normal physiological demands
Reversible cell damage- pathologic changes may be reversed once stimulus is removed
Irreversible cell damage- irreversible changes to structure and function
Virus induced cell injury
What is necessary for reversible injury to take place
State morphology of reversible cell injury
Oxygen must be present
Cellular swelling - hydronic or vacuoles change if there is a formation of vacuoles
Intracellular accumulation-
Of normal cellular constituents eg. TAG in fatty liver
Of abnormal substance - product of abnormal metabolism
Of a pigment
Depending on intensity and time can become irreversible
What morphological changes occur in irreversible cell injury?
Mitochondrial dysfunction - influx of Ca
Membrane damage - degradation of phospholipid membrane, cytoskeletal damage, toxic free radicals
Hydrolytic enzymes and release
State the differences between reversible and irreversible cell injury adaptive response, cell membrane function, global cellular response, mitochondria and nucleus response
Reversible cell injury- adaptive response of cell intact and balance injury, sodium potassium pumps malfunctions(electrolyte imbalance), swelling increase fat storage, swelling, rare fraction and lipid accumulation in mitochondria, aggregation of fibulae nuclear elements
Irreversible cell injury- adaptive response exceeded cannot restore, cell membrane starts to degrade, loss of cellular permeability(toxin formation, swelling leakage of cytochrome c into cytoplasm, dissolution of chromatin
Fb
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List the two important cell death
Apoptsis - expends energy to commit suicide eg embryogenesis
Necrosis- morphological changes that causes cell death (dead cells in living tissue and has INFLAMMATORY response)
List types of necrosis
Coagulation necrosis- changes in nuclear shape
Liquefaction necrosis- inflammation from infection
Caseous necrosis- related to tb (cheese appearance)
Fat necrosis - acute inflammation affecting adipoctyes such as enzymatic (pancreas) or non enzymatic (breast)
Dry gangrene necrosis- diabetic with cut on foot
Wet gangrene necrosis- bacteria block blood vessels to prevent immune system meeting tissue
State the two types of calcification and describe
Metastatic calcification- calcium deposits in previously normal tissue
Dystrophic calcification occurs in previously damaged tissue
