Acute Cell Injury and Death Flashcards
What are the causes of cell injury (9)?
oxygen deficiency, infectious agents, nutritional deficiency/imbalance, genetic derangement, workload imbalance, chemicals/drugs/toxins, immunologic dysfunction, aging
What is oxygen deficiency known as?
hypoxia
What are the physical agents that can cause cell injury?
heat, cold, radiation, toxins, and trauma
What are the infectious agents that can cause cell injury?
bacteria, viruses, parasites, proins
What are the types of genetic derangement?
inherited and acquired
What are the causes of hypoxia?
ischemia, anemia, carbon monoxide, respiratory failure, cardiac failure, thrombus/trauma
What is ischemia?
the loss of blood supply to a region
What is anemia?
decreased red blood cells and hemoglobin
How does carbon monoxide cause hypoxia?
CO binds to hemoglobin in oxygen place which leads to a decrease in oxygen
What can cause respiratory failure?
asphyxia and decreased gas exchange
What is the recurrent theme of cell swelling pathogenesis?
damage to the mitochondria leads to insufficient ATP production causing an inadequate functioning Na-K pump, then a net influx of Na and therefore water and the cell swelling
At what point is cell swelling irreversible?
when the mitochondria and cell membrane is damaged
What are the 3 forms of cell death?
necrosis, apoptosis, and post-mortem autolysis
What happens during necrosis?
the cell explodes, attracts neutrophils, and fragments are released into the extracellular space
What is apoptosis?
programmed cell death
What controls apoptosis?
nucleus
When a cell undergoes apoptosis, what happens to the cell fragments?
they become membrane bound and are eaten by other cells
Physiologically, what happens to cell size during apoptosis?
it shrinks
What are the triggers for apoptosis?
pathologic and physiologic
What are useful functions of apoptosis?
digit formation, cell infection, neoplastic, immune system, normal involution, old/senescent cells
What are some causes of membrane injury?
free radicals, carbon tetrachloride, beta radiation
What do free radicals cause?
lipid peroxidation
What does carbon tetrachloride cause?
cell swelling
What does beta-radiation cause?
loss of selective permeability
How does calcium play a role in cell death?
too much calcium in a cell can become mineralized very rapidly and be lethal to the cell
What organs does the build up of calcium most commonly affect?
skeletal and cardiac muscle
What does the significance of hypoxia depend on?
organ cell/type, degree, duration, and extent
Explain why degree affects hypoxia.
how bad the oxygen deficiency is depends on how bad the cells react
Explain why duration affects hypoxia.
how long the oxygen deficiency is depends on how bad the cells react or how lethal it is to the patient
What does a normal liver look like?
dark, smooth lobes, consistent in color, ‘jello-like’
If you cut a normal liver, what should happen?
if you cut it, it should go back to normal
Histologically, what does cell swelling look like in the liver?
there is space in between cells, more pale, larger, and some hepatocytes do not have nuclei or more than two
What are two reliable criteria you can use to tell whether a cell is dead or still reversibly swollen?
disruption of the cell integrity or nuclear morphology
