Pathology: Test 1: 04-05 Cellular and Tissue Accumulations I II Flashcards
- What are cellular adaptations and what causes them? <br></br>Give 4 kinds of cellular adaptation and briefly describe what each one does
a. Cellular adaptations are reversible functional/structural responses to sever physiological stress/pathological stimuli
<br></br>i. Hypertrophy: increase in size/functional activity of cell
<br></br>ii. hyperplasia: increase in # of cells
<br></br>iii. atrophy: decrease in size/metabolic activity of cells
<br></br>iv. metaplasia: change in cell phenotype
- When does cell injury occur? What are the stages of progressive impairment of the cell?
When limits of adaptive response to stimulus are exceeded
<br></br>Adaptation, reversible injury, and cell death represent stages of progressive impairment of cell’s normal function/structure
- What are the two patterns of cell death and how are they different from each other? Give an example of each
Necrosis: cell death after abnormal stresses (i.e. ischemia/chemical injury), always pathological
<br></br>Apoptosis: cell death occurring because of internally controlled suicide pattern (i.e. embryogenesis; withdrawal of hormones.
- What kind of cell process does nutrient deprivation trigger?
Autophagy (self-eating)
- What may cause subcellular alterations in a cell?
Cells exposed to sublethal or chronic stimuli.
- What are intracellular accumulations due to?
Metabolic derangements.
- Give and briefly describe two forms of metabolic (subcellular alterations) accumulations/deposits
(Intracellular accumulations due to metabolic derangements, depositing of i.e. proteins, lipids, carbohydrates)
<br></br>Pathological calcification: Ca deposits at site of cell death
<br></br>Cell aging: cells show morphological and functional changes
- What are physiological adaptations?
Responses to normal stimulation by hormones or endogenous chemical mediators (breast, lactation)
- How is pathological adaptations different/same than physiological adaptations?
Pathological adaptations share the same underlying mechanism, but they allow modulation of environment and ideally escape injury.
- What happens to cells in hypertrophy? Is it physiologic or pathologic? Caused by? Can occur in conjunction with? Most common stimulus for hypertrophy is?
<br></br>No new cells, just BIGGER cells, happens in non-dividing cells
<br></br>Can be both
<br></br>Caused by increased functional demand or specific hormone
<br></br>Can occur alone or with hyperplasia (increased # cells), if cells are able to divide
<br></br>Most common stimulus is increased workload
- What causes the physiological enlargement of the uterus?
Both hypertrophy of existing smooth muscle cells and hyperplasia of smooth muscle
- Give two examples of pathological hypertrophy occurring in the heart
What enlarges? When does it happen?
Cardiac enlargement that occurs with hypertension or aortic valve disease
Enlargement of individual cardiac fibers following an myocardial infarction (MI, heart attack) with death of surrounding myocytes (makes up for dead cells)
- How do striated muscle cells divide in the heart and skeletal muscle? Undergo what cellular adaption?
Cannot divide and make more cells, thus only hypertrophy
- What hypertrophies in the heart?
<br></br> when does this happen after?
Enlargement of individual cardiac fibers following an myocardial infarction (MI, heart attack) with death of surrounding myocytes
- In chronic cardiac overload, what genes are expressed? What does contractile proteins switch to?
Genes normally in neonatal heart reactivate <br></br>
Contractile proteins switch to fetal isoforms (contract slower)
- What is hyperplasia and what it result in? What does its occurrence depend on?
Hyperplasia: Increase in # of cells, leads to increased organ size and weight.<br></br>
Occurs if cell synthesize/mitosis
- What are the two kinds of physiologic hyperplasia?
Hormonal hyperplasia (increase function) e.g. lactating breast, pregnant uterus<br> Compensatory hyperplasia e.g. liver grows to make up for lost cells
- Pathologic hyperplasia usually results from?
Excessive hormones/growth factors
- Describe the pathological hyperplasia’s role in menstruation
Imbalance between estrogen and progesterone endometrial hyperplasia can occur (abnormal menstrual bleeding)
- What induces benign prostatic hyperplasia?
Androgens
- How are hormonal/growth factor stimulation and cancer different?
When hormonal/growth factor ceases, then stimulation ceases.<br></br>
In cancer however, cells continue to grow.
- What is responsible for hyperplasia’s healing ability? Give an example
Growth factors stimulated by viral infections, warts/papillomaviruses, etc.
- What are two stimuli for hyperplasia?
Increased growth factor, increased new cells from tissue stem cells
- Is atrophy physiological or pathological? Give an example
Both, physiological (embryonic structures) or pathological (atherosclerotic brain atrophy)
- Give 6 causes of atrophy
i. decreased workload<br></br>
ii. loss of innervation<br></br>
iii. decreased blood supply (senile atrophy)<br></br>
iv. inadequate nutrition<br></br>
v. loss of endocrine stimulation<br></br>
vi. pressure
- What does the decrease in cell size and organelles in atrophy reduce? Why?
Metabolic needs; permit survival
- The structural components of the cell reduced in number are because of what two reasos?
The structural components of the cell, are reduced in number due to?
Due to decreased protein synthesis<br></br> increase protein degradation
- What are autophagic vacuoles?
Accompanies atrophy and are fused lysosomes and intracellular organelles
- What happens to cell debris that resist digestion?
May persist as membrane-bound residual bodies (i.e. lipofuscin)
- What is metaplasia and why does it occur?
Reversible change in cell type to another. Cells stressed are replaced by cells types better able to withstand (columnar -> squamous, as in resp. tract)