Irreversible Cell Injury & Cell Death Flashcards
Severe and persistent cell injury, severe cell membrane dysfunction and mitochondrial damage, increased intracellular Ca levels, “the point of no return”
Irreversible cell injury
Cell death can be divided into two categories, they are…
Necrosis and apoptosis
Physiologic cell death or programmed cell death
Apoptosis
Pathologic cell death
Necrosis
Necrosis characterized by cell swelling to the point of membrane rupture
Oncotic necrosis
Name the category of oncotic necrosis morphology:
Visible swelling, ruptured plasma membrane and organelles, ruptured nucleus, mitochondria swollen with amorphous densities
Ultrastructural
Name the category of oncotic necrosis morphology:
Hypereosinophilic cytoplasm (denatured proteins + loss of ribosomes), nuclear changes (pyknosis, karyorrhexis, and karyolysis)
Microscopic
Nuclear condensation with shrinkage and intense basophilia
Pyknosis
Nuclear fragmentation
Karyorrhexis
Nuclear dissolution or loss
Karyolysis
Name the category of oncotic necrosis morphology:
Swelling and pallor (soon after cell death), loss of structural detail, demarcation from adjacent viable tissue, discolored, soft, appearance highly variable depending on many factors
Macroscopic/Gross
What are the 4 main classifications of necrosis?
Coagulation, caseous, liquefactive/lytic, gangrenous
Type of necrosis typically caused by hypoxia, ischemia, or toxic injury; general tissue structure preserved, cell outlines recognizable, nuclei loss, pale tan/gray or red, solid, and often sharply demarcated from adjacent viable tissue
Coagulation necrosis
A focal area of coagulation necrosis resulting from failure of blood supply (ischemia)
Infarct
When blood enters infarcted tissue because blood flow is restored in the obstructed vessel, or arrived from collateral circulation, it creates a…
Hemorrhagic infarct
When macrophages remove the blood from an acute hemorrhagic infarct, it creates an…
Ischemic (pale) infarct
Obstruction of the venous system by thrombus or external compression creates a…
Venous infarct
(Examples: infarcts created by intestinal volvulus or strangulation lipomas)
Type of necrosis with curdled-cheese gross appearance; older lesion, compete loss of cellular/tissue architecture, cell outlines not visible; crumbled, granular consistency with yellow-white color; mineralization common
Caseous necrosis
Example: Mycobacterium spp (tuberculosis)
Type of necrosis where tissue is in a fluid phase; cells lysed by lytic enzymes of neutrophils; yellow, soft, liquid consistency; loss of tissue/cellular structure, cell outlines not visible; the only kind of necrosis found in the CNS
Liquefactive necrosis
Examples: necrosis of CNS (lack of fibrous tissue to uphold tissue structure) and infection of pyogenic bacteria (at the center of abscesses)
The lessening of density of tissue; loss of neuropil in terms of liquefactive necrosis
Rarefaction
A form of infarction due to loss of blood supply found at the distal aspect of extremities; dry leathery texture, free of bacteria
Dry gangrene
Necrotic tissue invaded by bacteria that occurs commonly in the lungs (aspiration pneumonia) and mammary glands
Wet gangrene
Necrotic tissue invaded by gas forming bacteria
Gas gangrene
Necrosis that occurs secondary to leakage of pancreatic enzymes (lipases) in pancreatitis cases
Enzymatic fat necrosis
