1 - Cell Adaptation Flashcards
(28 cards)
Etiology
Origin of disease
Pathogenesis
The steps in development of disease
Diverse causes of cell death (examples)
ischemia, infections, toxins, immune reactions
Cell death is sometimes an ___ and ____ process
essential and normal
Reversibly injured myocytes are not ___ and may resemble normal myocytes morphologically
BUT they are ________ so they are susceptible to mild injury
Not dead
Transiently non-contractile
Whether stress causes adaptation or death depends on ___ and ____ of the stress, as well as other variables such as….
Nature and severity
Basal cellular metabolism, blood and nutrient supply
Cell adaptations are changes in…
Number Size phenotype metabolic activity function
- Physiologic adaptations represent responses of cells to…
- Pathologic adaptations allow cells to modulate…
- Normal stimulation by hormones or endogenous chemical mediators
- Stresses that allow cells to modulate structure/fxn
Example of physiologic hypertrophy
striated muscle hypertrophy
Example of pathologic hypertrophy
Cardiac enlargement from HTN or aortic valve disease
Two mechanisms for cardiac hypertrophy
- Mechanical trigger
- Trophic triggers
Examples of each?
- Mechanical = stretch
2. Trophic = soluble mediators such as Growth Factors and Adrenergic hormones
During muscle hypertrophy, _____ chain is replaced by ______ which produces…
ALPHA myosin chain is replaced by BETA
Produces slower, more energetically economical contractions.
What are the reasons for the limited changes in myocytes during hypertrophy, and what structural shift does this cause?
Finite limits of vasculature, ATP (Mito), or biosynthetic machinery for contractile proteins.
= Ventricular dilation (and ultimately cardiac failure)
Two types of physiologic hyperplasia
Hormonal (glandular type such as breast tissue)
Compensatory (such as liver)
Stimuli for liver hyperplasia after resection
Polypeptide growth factors from uninjured cells and nonparenchymal cells in liver
Most forms of pathologic hyperplasia are caused by excess ______
hormonal or growth factor stimulation
Example of pathologic hyperplasia?
Endometrial hyperplasia caused by imbalanced estrogen and progesterone
Endometrial hyperplasia commonly causes…
Abnormal menstrual bleeding
In wound healing, growth factors are produced by _____
leukocytes and cells in ECM
Distinction of hyperplasia from cancer.
Hyperplasia will stop upon cessation of signal, whereas in cancer the growth becomes dysregulated.
Causes of cell atrophy
Lowered workload denervation diminished blood supply inadequate nutrition or endocrine stimulation aging
Mechanism of atrophy is a combination of ___ and ___
decreased protein synthesis and increased protein degradation
Protein synth reduction in atrophy is due to
lowered metabolic activity
Degradation of cellular proteins in atrophy is mainly via _____. How?
Ub-proteasome pathway
Nutrient deficiency activates Ub-LIGASES
