Cellular Injury Flashcards
Adaptation to physiological stress and noxious stimuli is reversible or irreversible -
reversible
Hypertrophy
increase in cell size due to the synthesis of more cellular or cytosolic components (or increase in size of organelles)
Signal transduction pathway of stressors lead to
a stress (mechanical trigger)
Release of different GF or hormones (tropic factors) depending on the stressor
Physiologic hypertrophy
training athlete has a larger heart than a sedentary person which leads to a lower resting HR because the heart is larger, has more muscle, stronger, ejects more blood (a stronger heart with thicker walls)
Pathologic hypertrophy
chronic, uncontrolled hypertension causes heart to enlarge; must overcome increased pressure in arteries to eject blood which causes an increase in work demand or metabolic demand or excess endocrine stimulation
Pathologic hypertrophy can lead to what and why
progress to heart failure if BP is not reduced, heart can no longer adapt so this continued stress will lead to cell injury
Hyperplasia
increase in number of cells; cells must be able to divide and/or stem cells present
Physiologic hyperplasia
Pregnancy: hormonal hyperplasia (estrogen and progesterone leading to breast and uterus enlargement)
Remove part of liver: compensatory hyperplasia (increased growth factor leads to liver tissue regen)
Uterus enlargement is a result of
hyperplasia and hypertrophy
Pathologic Hyperplasia
Prostate: DHT –> BPH (enlarged prostate)
End of uterus cycle: estrogen, progesterone out of balance to inhibit sloughing –> endometrical hyperplasia
Gingival hyperplasia: drug induced by decreasing Ca channel blockers
Compensatory hyperplasia
Removing part of the liver and it growing back
Cause of gingival induced hyperplasia
drug induced- drug induced by decreasing Ca Channel blockers
Requirement for tissue to be able to develop hyperplasia
cells need to be able to divide
Atrophy (define)
loss of muscle mass, loss of cellular substance –> decreased cell size
Atrophy (cause)
loss of stimulation (nervous or hormonal), inadequate blood supply and inaqequate nutrients
loss of stimulation (nervous or hormonal), inadequate blood supply and inaqequate nutrients leads to what (3)
Reduced metabolic activity (reduced prt synthesis)
Stimulate prt degradation
Autophagy
During nutrient deprivation (or to clear misfolded
proteins), SER membrane encircles organelles to form
autophagic vacuole –> fuses with lysosome –> digest
cellular components
Why do cells atrophy
So they can control their internal environment and produce energy to survive –> fewer organelles means less ATP needed
Metaplasia
the conversion of one cell type to another
GERD (an example of what) and explain what happens
lining of esophagus (stratified squamous epithelium) becomes
same cell as lining of stomach (simple columnar epithelium with
mucus and bicarbonate producing cells)
GERD pro and con
Good in that it protects from acid better
Bad in that its worse protection from abrasion and can increase the risk of esophageal cancer
Relationship between metaplasia and cancer
normal cells can convert to cancerous ones- increases the risk for esophageal cancer
Mens Prostate cellular response
Prostate: DHT –> BPH (enlarged prostate)
Finasteride is a drug that inhibits the conversion of testosterone to dihydrotestosterone. What affect will it have on a person with benign prostatic hyperplasia (BPH) and how quickly will this happen?
A. Decrease the hyperplasia and cause shrinkage of the prostate in a few hours B. Decrease the hyperplasia and cause shrinkage of the prostate in a few months C. Increase the hyperplasia and cause further prostate enlargement in a few hours D. Increase the hyperplasia and cause further prostate enlargement in a few months
Decrease the hyperplasia and cause
shrinkage of the prostate in a few months
Microscopic evaluation of a tissue obtained from a surgical procedure showed that multiple cells had an increased cell size due to an increase in the amount of cytoplasm, but nuclei remained uniform in size. Which of the following tissues and conditions is most likely to have resulted in this finding?
A. Bronchial epithelium with chronic irritation
B. Liver following partial resection
C. Ovary following menopause
D. Skeletal muscle in the lower limb of a
quadriplegic
E. Uterine smooth muscle in pregnancy
Uterine smooth muscle in pregnancy
Denervation of skeletal muscle or dramatically reduced use of skeletal muscle or bone?
hypertrophy
Chronic irritation, such as with acid reflux into the esophagus, or smoking’s effect on the trachea/bronchial epithelium?
metplasia
Lose hormones following menopause
atrophy
Cell injury by Hypoxia can be caused by what (3 thing)
Ischemia (reduced blood flow)
Reduced O2 carrying capacity (anemia with decreased iron and hemoglobin, CO poisoning)
Respiratory failure (reduced oxygenation in the blood)
Events following reversible cell injury
Biochemical cell changes leading to decreased cell function –> ultrastructural changes (damaged organelles or cytoskeleton) –> light microscopic changes –> gross morphological changes
Cell swelling (hydropic change or vacuolar degeneration) reversible injury microscopic changes
- loss of microvilli
- cell swells –> ER Swells –> can pinch off and form vacuokes (distended, pinched off segments of ER)
- “Blebs”
- Darker pink stain=increased protein coagulation
- increased weight –> increased turgor (more firm)
- increased pallor (more pale) b/c compression of capillaries and decreased blood flow
Is cell swelling reversible or not?
yeah, as are its effects
Necrosis, reversible or not?
No
Necrosis (irreversible) biological changes
Sequential development of biochemical and morphological changes
Biological changes and cell death –> ultrastructural changes –>
light microscopic changes and gross morphological changes
that are MUCH more prevalent
Cell appearance of necrosis
leakage of cell content, cell fragmentation more
prevalent than whole cells, cytoplasm “moth eaten” from digested organelles, loss of or odd looking nuclei, increased eosinophilia in
cytoplasm
Nuclei in necrosis
Pyknosis: Irreversible condensation DNA chromatin –> solid,
shrunken, dark mass
- Karyorrhexis: nucleases are released –> pyknotic nucleus
fragments - Karyolysis: DNase activation–> chromatin dissolution
Nuclei in necrosis
Pyknosis: Irreversible condensation DNA chromatin –> solid,
shrunken, dark mass
- Karyorrhexis: nucleases are released –> pyknotic nucleus
fragments - Karyolysis: DNase activation–> chromatin dissolution
(do not see nucleus)
How does the body respond to necrosis
by inflammation due to the release of cellular contents
Pyknosis:
Irreversible condensation DNA chromatin –> solid,
shrunken, dark mass
Karyorrhexis:
nucleases are released –> pyknotic nucleus
fragments (nuclei are broken up)
Karyolysis:
DNase activation–> chromatin dissolution (do not see nucleus)
Feature of coagulative necrosis
in a solid organ (cells stay intact)
Characteristics of coagulative necrosis and what causes each (2)
PALE-loss of blood so caused by ischemia
Wedge shaped: blood supply to this area is lost (ischemia)