Introduction to Cell Injury, Types of Necrosis Flashcards
What is the mechanism of hypoxia-induced cell death?
oxidative phosphorylation
what are physical injuries that cause cell injury and death?
mechanical trauma, such as motor vehicle accidents, temperature extremes (burns and deep cold), electrical shock (lightning), and radiation.
what is the target theory of radiation induced cell injury?
radiant energy makes a direct hit on bonds within DNA of a cell. This attack on DNA may lead to mutations having genetic or cancerous potentials (watch that suntan) or to inhibition of cell division and cell death.
what is the indirect hit theory of radiation induced cell injury?
radiant energy exerts its effect by producing free radicals which interfere with critical cellular components, such as membranes, nucleic acids, and enzymes, leading to cell death
what is the most common source of radiant energy induced damage to animals and humans?
sun
what is the mechanism of poisoning by cyanide?
Cyanide interferes with oxidative phosphorylation by blocking the terminal step in the electron transport chain. It does this by forming a stable, irreversible complex with the cytochrome a3 subunit of cytochrome C oxidase, making it unable to transport electrons.
CYANIDE INHIBITS OXIDATIVE PHOSPHORYLATION ->STOPS ELECTRON TRANSPORT ->CELL DEATH
how can animals die from cyanide?
plants, such as the chokecherry contain the toxic substance hydrocyanic acid (or prussic acid)
what is the pathogenesis of herpes causing cell death?
VIRUS IN CELL ->CELL NECROSIS ->MUCOSAL ULCERATION ->HEMORRHAGE & INFLAMMATION
how does a deficiency of Selenium or vitamin E cause cell injury and death?
IT CAUSES FREE RADICAL ACCUMULATIONS WHICH DAMAGE VITAL CELL COMPONENTS
Vitamin E and selenium containing enzymes are required in order to scavenge free radicals. Free radicals may initiate cellular injury by causing peroxidation of membrane lipids and by causing physiochemical damage to protein molecules.
what organelles is swelling most apparent?
endoplasmic reticulum and mitochondria
With failure of the Na-K ATPase pump (due to lack of ATP) or compromise of the cell membrane, what is there an influx of?
Na+, Ca++, and H20
what substances may vacuoles in hepatocyte cytoplasm contain besides water?
glycogens and sometimes lipids
what kind of necrosis is an abscess an example of?
liquefactive necrosis
what type of tissue is particularly prone to liquefactive necrosis?
CNS (termed malacia)
what is the most common type of necrosis
coagulative
