Cell death, Necrosis and apoptosis Flashcards
What happens if the stress persist for a long time
Then the cell will experience cell death
What is the hallmark of cell death
the death or loss of the nucleus
What are the mechanism of how you can lose the nucleus?
Pyknosis (shrinking of the nucleus), Karyorrhexis (breaking up of the nucleus into pieces) and Karyolysis dissolution of the nucleus)
What are the two mechanism of cell death?
Necrosis (murder) and Apoptosis (suicide)
What is Coagulative necrosis
tissue the is necrotic but firm Coagulative Necrosis - becomes firmer in the organ. it is a type of accidental cell death typically caused by ischemia or infarction. also this tissue has been dead for a couple of day. the nucleus disappears.
What is liquefactive necrosis
pick for infraction in the brain. there is no infraction in the brain other than this. This is a result in a transformation of the tissue into a liquid viscous mass by an enzyme. it is associated with focal bacterial or fungal infection. There will be a missing piece of the brain. For liquefactive, macrophage clean up the lips debris.
What is the organ that Coagulative Necrosis will never occur
the Brain
What is red infarction
it is when the blood reenters the organ in a loose tissue.
What are the normal location of liquefactive necrosis
Brain
abscess
Pancreatitis
What is Gangrene necrosis
it is a coagulative necrosis that resembles mummified tissue
What is the big characteristic of Gangrene necrosis
ischemia of ewer limb and GI tract
What are the two types of gangrene
wet and dry
What happens if there is a infection that occurs while having gangrene
wet gangrene (pus)
What happens when gangrene is in the bloodstream
it is called sepsis.
What is Caseous necrosis
is a form of cell death in which the tissue maintains a cheese-like appearance ( Friable- it crumbs). The dead tissue appears as a soft and white proteinaceous dead cell mass.
What are the causes of Caseous necrosis
it is from an encounter tuberculous infections and also syphilis and certain fungi. you will have to do an acid fast stain to diagnose the necrosis. the area of caseous necrosis is often closed with a distinctive inflammatory border is granuloma.
What is Fat necrosis
adipose tissue with a chalky whit appearance due to the deposition of calcium
What is the enzyme that is involved in fat necrosis
In fat necrosis the enzyme lipase releases fatty acids from triglycerides. The fatty acids then complex with calcium to form soaps. These soaps appear as white chalky deposits.It is usually associated with trauma of the pancreas or acute pancreatitis.I
Where do you see fat necrosis
breast and pancreatitis mediated damage of peripacreatic fat
What is Fibrinoid Necrosis
necrotic damage to blood vessel wall and the leaking of proteins into the vessel wall resulting in bright pink stain
What is Saponification
Fatty acids released by trauma or lipase join with calcium. (soap)
What is apoptosis
energy ATP dependent, genetically programmed cell death involving single cells or small groups of cells.
What is fibrinoid necrosis associated with
vasculitis, malignant hypertension, preeclampsia or hyperacute transplant
What are examples of apoptosis
endometrial shedding during menstrual cycle
removal of cells during embryogenesis
CD8 T-cells mediated killing of virally infected cells
What are the ways that apoptosis can happen
blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, chromosomal DNA fragmentation, and global mRNA decay.
What is the key mediator of apoptosis
caspases. they activate proteases and endonucleases
What are the two pathways of apoptosis
Intrinsic mitochondrial and Death receptor
What is intrinsic mitochondrial pathway
his deals with something that force that cause apoptosis. this force would be cell injury, DNA damage (cancer), or decrease of hormonal stimulation
What is the key to intrinsic mitochondrial pathway
Cytochrome C. BCL2 is used to stabilize the mitochondria for Cytochrome C so it doesn’t leak. If there is damage to BCL2, then Cytochrome C leaks and activates capases.
What is Extrinsic receptor ligand pathway ( Death receptor)
FAS ligand binds to the FAS death receptor on the target cell. Some from the outside world finds a receptor that activates apoptosis.
What is the process of the Extrinsic receptor pathway
This comes from the T-cells coming from the bone marrow and needed to get information from the thymus on what to do. it goes through 2 selections in order to do that.
Positive selection: t-cells are asked can the bind Self antigen plus MHC. If yes, it survives and goes on to the next test
Negative selection: T-cell are asked do you bind self antigen to strongly? if yes, the cell is destroyed during this selection.
