cell adaptation Flashcards
the cell can adapt to changes/stimulation
cell adaptation
increase in cell with subsequent increase in organ size
hypertrophy
causes of hypertrophy
increase functional demand, hormonal stimulation
increase in the number of cells in an organ which may then increase organ size
hyperplasia
the female breast at puberty and in pregnancy
hormonal hyperplasia
liver regeneration after partial resection
compensatory hyperplasia
causes of pathologic hyperplasia
excess hormones
increased risk for development of endometrial adenocarcinoma
atypical hyperplasia
decrease in the size of cell of organ by loss of cell substance can either be both size and number
atrophy
physiologic atrophy
normal development, uterus following childbirth
causes of pathologic atrophy
decreased workload, loss of innervation, decreased blood supply, inadequate nutrition, loss of endocrine stimulation and pressure
atrophy results from both what?
decreased protein synthesis and increase protein degredation
incomplete development of an organ so that it fails to reach adult size or the decrease in cell production
hypoplasia
a reversible change in which 1 adult cell type is replaced by another adult cell type.
metaplasia
what is associated with vitamin a that is caused by chronic irritation and vitamin a deficiency?
metaplasia
hyperplasia and metaplasia are _______ changes but a fertile field of dysplasia which is a ______ change.
not premalignant, premalignant
atypical proliferative changes due to chronic irritation or inflammation
dysplasia
the principles of cell injury
a. the cellular response to injurious stimuli depends on the type of injury, its duration and its severity.
b. the consequences of cell injury depends on the type, state and adaptability of the injured cell.
c. cell injury results from different biochemical mechanisms acting on several essential cellular components.
the reversible changes secondary to injury
cellular swelling, cell membrane blebs, detached ribosomes, & chromatin clumping,
the irreversible changes secondary to injury
lysosome rupture, dense bodies in mitochondria, cell membrane rupture, & karyolysis, karyorrhexis and pyknosis.
melting/dissolution of nucleus
karyolysis
fragmentation of nucleus
karyorrhexis
the nucleus is shrunken and dark, or the shrinkage of nucleus
pyknosis
myocardial infarction markers
a. 2 hour post infarction - cardiac specific enzymes and proteins
b. 4-12 hours - morphologic changes
cell proliferation:
a. continuously dividing cells
b. quiescent cells
c. non-dividing cells
a. labile cells
b. stable cells
c. permanent cells
susceptibility to ischemic necrosis
high: neurons (3-4 mins)
medium: myocardium, hepatocytes, renal epithelium (30 mins to 2 hours)
low: fibroblast, epidermis, skeletal muscles (many hours)
3 major consequences of mitochondrial damage
- mpt pores open, loss of mitochondrial membrane potential. decreased oxidative phosphorylation and decreased atp.
- production of ROS
- leakage of pro-apoptic proteins
loss of ca++ homeostasis
a. extracellular is 15x higher than cystosolic ca++
b. loss of atp increases intracellular
c. increased ca++ also increases mitochondrial permeability triggering apoptosis
normal metabolism produces..
superoxide anion, hydrogen peroxide and hydroxyl ion
superoxide is produced in ___
neutrophils
excess ROS leads to
oxidative stress
pathologic effects of ROS
a. lipid peroxidation (membrane damage)
b. protein damage
c. dna damage
what blocks the formation of ROS or inactivates them
antioxidant
the antioxidant enzymes
superoxide dismutase, catalase, glutathione peroxidase
vitamins associated with antioxidant
vitamins a, e, c (ascorbic acid), glutathione
membrane permeability defects
a. plasma membrane
b. mitochondrial membrane
c. lysosomal membrane (release of rnas, dnas, and proteases)
cell injury causes
- oxygen deprivation
- physical agents
- chemical agents and drugs
- infectious agents
- immunologic reactions
- genetic derangements
- nutritional imbalances
known as the deficiency of oxygen
hypoxia
causes of hypoxia
cardiorespiratory failure, anemia, co poisoning
known as the loss of blood supply (oxygen and nutrients)
ischemia
death of groups of cells after injury & usually with inflammation
necrosis
death of individual cells usually no imflammation
apoptosis
the hypoxic death except brain
coagulative
bacterial infections, also hypoxic death in brain tissue
liquefactive
associated with tuberculosis in terms of necrosis
caseous
enzymatic or traumatic damage to fatty tissue like pancreatitis
fat
usually involves lower extremities and often is a type of coagulative necrosis
gangrenous
immune complexes in arteries
fibrinoid
the failure of an organ to develop during embryonic growth and development due to the absence of primordial tissue
agenesis
failure of the corpus callosum to develop
agenesis of the corpus callosum
failure of 1 or both kidneys to develop
renal agenesis
failure of the arms or legs to develop
phocomelia
failure of the penis to develop
penile agenesis
failure of the uterus and part of vagina to develop
mullerian agenesis
failure of the gallbladder to develop
`agenesis of the gallbladder
failure of the portion of the eyelid margin to develop
eye agenesis