Altered Cell Biology Flashcards
stress (insult)
stimulus that upsets normal homeostasis
Compensation
the body’s attempt to maintain normal homeostasis under stress
cell injury
result of a stimulus in excess of a cell’s immediate adaptive response
reversible cell injury
injury which does not kill the cell (makes it stronger)
apoptosis
- clean, controlled cell death
- cell breaks apart into apoptotic bodies that then get phagocytozed by other cells
- membrane is not ruptured
- no enzymes released
- does not trigger immune response
- does not show in blood test

Necrosis
- messy, uncontrolled cell death
- cell membrane breaks
- causes release of enzymes
- causes inflammatory response
- shows in blood test

atrophy
decrease in the size of cells

hypertrophy
increase in the size of cells

hyperplasia
increase in number of cells

metaplasia
- change of the cell from one type to another
- can be normal or abnormal
- ex. GERD, cells of esophagus change over time to become more like the cells of the stomach from all the acid.

dysplasia
- abnormal cells that are not necesarily cancer, but can be
- change from normal to abnormal
- ex: a wort

neoplasia
- abnormal disorganized growth, if it forms a mass, is called a tumor
- *different from dysplasia because it is larger in size

how does heart muscle get bigger?
- only 1% more cardiomyocytes are made by stem cells per year.
- the individual cardiomyocyte cells grow bigger, making the overall muscle bigger.
What are the four common themes in cell injury?
- ATP depletion
- free radicals and reactive oxygen species
- Increase in intracellular Ca++
- Defects in plasma membrane
ATP depletion
- lack of O2 greatly decreases ATP production
- lack of ATP prevents the Na/K channels from working
Free radicals and reactive oxygen species
- highly reactive chemicals containing oxygen
- Cause oxidation of membranes and other structures
- particularly problematic with reperfusion
Increase in intracellular Ca++:
what can cause it?
what does it cause?
- low ATP and Na+ gradient prevent removal of Ca++ and release of Ca++ from mitochondria and ER
- Ca++ activates many enzymes
- at very high levels Ca++ signals apoptosis
What is the process of a cell being injured by ischemia?
(flow chart)

what changes happen to a cell that makes the injury irreversible?
- rupture of lysosoves and autolysis
- defects in the cell membrane
- karyolysis
- karyorrhexis

karyolysis and karyorrhexis
breaking up of chromatin and the cell nucleus/DNA
hypoxia
low tissue oxygent level
anoxia
very low tissue oxygen level, no oxygen
hypoxemia
low blood oxygen tension
how does anemia effect hypoxia and hypoxemia?
An anemic person can have a normal oxygen tension (because all their hemoglobin are 100% saturated) but low tissue oxygen level because they don’t have enough hgb to bring enough O2 to the tissues.


