Cellular Adaptation - ANSWER - Diseases begin with cellular alterations
- Extent of injury depends on:
*Type, state, adaptive processes of cell
*Type, severity, and duration of injurious stimulus
- Can be reversible
- All diseases exert their effects on the smallest living unit: the cell
- Cells adapt to changes in the internal environment just as the total
organism adapts to changes in the external environment
- When the stress is overwhelming or adaptation is ineffective: injury,
maladaptive changes, and cell death occur
- Pathological: abnormal, disease
- Physiological: normal
Atrophy - ANSWER - Decrease in cell size
- Occurs when cells have a decrease in work demand or adverse
environmental conditions; adapt to survive
- Atrophied cells use less oxygen and reduce other cellular functions by
decreasing the number and size of organelles an other structures
- When enough cells experience atrophy, the entire tissue atrophies.
,- Five groups of causes: 1. disuse 2. denervation 3. loss of endocrine
stimulation, 4. inadequate nutrition, and 5. ischemia or decreased blood flow
Hypertrophy - ANSWER - Increase in cell size
- Increased cell size results in increased amount of functioning tissue mass --
involves an increase in the functional components of the cell that allows
equilibrium between demand and functional capacity -- can result from
normal physiologic or abnormal pathologic conditions
- Physiologic (normal functioning): increased muscle mass with exercise
- Pathologic (abnormality/disease state): result of disease -- Can be adaptive
or compensatory:
*Adaptive: myocardial hypertrophy from valvular heart disease or HTN
*Compensatory: enlargement of remaining kidney after one is surgically
removed-compensation.
Hyperplasia - ANSWER - Increase in number of cells
- Occurs in tissues with cells capable of mitotic division (epidermis, intestinal
epithelium, glandular tissue)
Physiologic (2) types:
- Hormonal: Uterus during pregnancy
- Compensatory: Liver regeneration after partial hepatectomy
- Also important in wound healing (fibroblasts and blood vessels)
Nonphysiologic: Results from excessive hormonal stimulation or effects of
,growth factors on target tissues (Ex. Skin warts secondary to HPV)
Stress cells may fill up with these (intracellular accumulations) - ANSWER -
Substances may accumulate in the cytoplasm or nucleus
- Normal body substances: Lipids, proteins, pigments. produced faster than
metabolism or removal (ex: fatty liver)
- Abnormal endogenous substances:
Metabolic products—glycogen, lipids, May result from genetic disorders
hindering degradation of a substance or interrupting transfer of a substance
to another site (ex: Tay sachs)
- Abnormal exogenous substances: Pigments -May be transient or
permanent, might be harmless or toxic. The significance of intracellular
accumulations depends on the cause and severity of the condition. For
example: hyperbilirubinemia is reversible but glycogen storage diseases
result in organ dysfunction.
**Endogenous: Icterus/jaundice secondary to retention of bilirubin
**Exogenous: Coal dust
Dyplasia - ANSWER - Deranged cell growth resulting in cells that vary In size,
shape, and organization
- Minor _______ associated with chronic irritation or inflammation. Usually
respiratory tract or uterine cervix
- Is abnormal but is considered adaptive because it can be reversible if
irritating factor is removed. Highly associated with cancer but does not
always lead to cancer
, - Can be reversed
- Pap test: cervical cancer develops in incremental epithelial changes
Metaplasia - ANSWER - Reversible change in which one adult cell type is
replaced by another adult cell type (always within boundary of primary tissue
type)
- Thought to involve the reprogramming of undifferentiated stem cells.
Usually in response to chronic irritation and inflammation. Cells better able
to survive than more fragile cells they are replacing. (Ex. Tracheal changes in
long-term cigarette smokers).
- Continued exposure to the causes for metaplasia could result in cancer
- Physical: trauma, heat and cold, electricity
- Radiation: ionizing, ultraviolet, non-ionizing
- Chemical: drugs, lead, mercury
- Biologic agents: bacteria, viruses, parasites
- Nutritional imbalances: fats, minerals, vitamins, amino acids In health, cell
injury and death are balanced by cell renewal (ongoing process). .
Extra notes from kara's powerpoint
- Physical: -Extreme temperatures cause damage to cells including the
organelles & enzyme systems
- Low-intensity heat: causes vascular injury, accelerated cell metabolism,
enzyme and cell membrane disruption -- with increasing heat comes
coagulation of blood and tissue proteins
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Smooth. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $13.99. You're not tied to anything after your purchase.