Sublethal cellular responses Flashcards
what is homeostasis
steady state maintained in response to physiological demands
4 possible responses to stress
- adaptation (plasias)
- Other cell alterations
- cell injury
- cell death
3 purposes of adaptive cell repsonses
- withstand stress
- adapt to stress
- restore tissues to normal function
4 types of adaptations
- hyperplasia
- hypertrophy
- atrophy
- metaplasia
def. hyperplasia
increase in # of cells, resulting in increased mass of tissue or organ
2 features of hyperplasia
- occurs in cells capable of replication
2. reversible
mech. of hyperplasia
stim of cell cycle by growth factors, more mature cells
4 pathologic hyperplasia
- endometrial
- prostatic
- ductal of breast
- repsonse to viruses
2 phsyiological hyperplasia
- hormonal
2. compensatory
def. hypertrophy
increase in cell size leading to larger organ
3 feat. of hypertrophy
- oft. coexists with hyperplasia
- cell enlargement
- reversible
mech of hypertrophy
increased synthesis of structural proteins and cellular components
2 physiological hypertrophy
- excercise
2. hormonal
2 pathological hypertrophy
- cardiac muscle
2. bladder muscle
def. atrophy
decrease in size and/or number of cells
is atrophy reversible?
yes
2 normal atrophy
- embryo
2. reversal of hyper
mech of atrophy
increased protein degradation and decreased synthesis
5 examples of pathological atrophy
- decreased worload
- loss of innervation
- loss of blood supply
- lack of nutrition
- loss of hormones
def. metaplasia
change of one MATURE cell type to another
4 feat. of metaplasia
- epithelial or mesenchymal cells
- adaptive to changing env.
- response to chronic irritation
- prob. not reversible
normal metaplasia
ONLY one - squamous metaplasia in cervix
mech of metaplasia
reporogrammming of epithelial stem cells
4 patho metaplasias
- squamous meta of bronchi
- columnar meta of esoph
- intestinal meta of stomach
- squamous meta of bladder
3 other cellular alterations
- aging
- accumulation of cell contents
- dysplasia/neoplasia
2 types of cell accumulations
- normal - water, lipids, protein
2. abnormal -endogenous or exogenous
4 features of accumulation
- transient or perm
- harmless of toxic
- cytoplasm or nucl.
- produced by the cell or just stored there
4 types of patho cell contents
- steatosis (fatty) liver
- gauchers
- alzheimers
- parkinsons
what is normal protein folding
translation and folded with help of chaperones
3 options if protein not folded properly
- repair
- ubiquitin-proteasome degradation
- cell damage and apop
what is amyloid
pathologic protein that is abnormall folded in B-pleated sheets - resitant to degradation
3 types of amyloid
AL - immunoglobin light chain
AA - acute phase
AB - alzheimers
what are prions
abnormally folded proteins that can cause other near proteins to fold - mad cow
def. neo and dysplasia
cellular alteration resulting in disordered or uncontrolled growth
def dysplasia
pre-malignant and MAY be reversible
def. neoplasia
refers to a tumor which has lost normal growth control and usually irreversible
mech in neoplasia
alterations in genes that control cell growth an survvial - esp in cells that proliferate
are dysplasic benign?
NOT neccesarily
