Mechanisms of Cell Injury Flashcards
what are 5 categories of causes of cell injury’s
injury from: physical agent radiation injury chemical injury biological agent nutritional imbalances
first indication of cell injury is
biochemical lesion @ point of injury -:>lesion changes chemistry of metabolic reactions with in the cell
types of physical agents that cause cell injury
mechanical forces, extremes of temp,
electrical forces
mechanical injury forces occur (physical injury)
when body impacts with another object
tissue or bone tear, fracture, blood vessels can be injured to disrupt blood flow
extreme temp (physical injury)
causes damage to the cell, its organelles, and enzyme systems
low intensity heat causes (physical damage)
causes partial thickness burn or sever heat stroke
causes cell injury by causing vascular injury->accelerates cell metabolism, inactivates temp sensitive enzymes and disrupts cell membrane
more intense heat (physical damage)
coagulation of blood vessels and tissue proteins occur
cold exposure temp (physical damage)
increase blood viscosity, induces vasoconstriction as a reflex of sympathetic nervous system-> decreased blood flow may lead to hypoxic tissue injury
cold exposure temp can lead to (physical damage)
hypoxic injury due to capillary stasis and thrombosis
hypoxic means
deprived of adequate oxygen supply at tissue level
freezing (physical injury)
may result from a combo of ice crystal formation and vasoconstriction leads to edema
electrical forces (physical injury)
can affect body through ext. tissue injury and disruption of neural and cardiac impulses
much of damage caused by electrical injury is caused by
heat production in tissue that have highest electrical resistance
radiation injury types
ionizing radiation
UV and non-ionizing
ionizing radiation injury
causes release of free radicals that destroy cells->can kill cells or interrupt cell replication or cause variety of genetic mutations
example of ionizing radiation
cancer treatment
UV radiation
causes sunburns, increase risk of skin cancer
uv radiation damage caused
from reactive oxygen species (ROS) (free radicals) and damage to melanin producing processing the skin to damage DNA
non-ionizing radiation examples
infrared light, ultrasounds, microwaves, laser energy
non-ionizing radiation causes
direct break of chemical bonds caused by vibrations and rotation of atoms and molecules, energy converted into thermal energy, can burn skin and cause thermal injury to dermal subcut, and deeper tissue
types of chemical injury
drugs, lead toxicity, mercury toxicity,
examples of chemicals that can damage cells
carbon tetrachloride when ingested, tobacco when inhaled, preservatives, carbon monixde
drugs (chemical injury)
affects cells/tissue based on chemical nature of drug and how it is metabolized can impact cells, tissues, and organs
how does alcohol cause damage
can harm gastric mucosa, live developing fetus, can directly or indirectly damage tissue
acetaminophen damages (drug/chemical injury)
detoxed in liver- converted to toxic metabolite->detoxed by pathway that uses sub-> but when in large amounts, pathway is overwhelmed and toxic metabolite accumulates causing liver necrosis
lead toxicity (chemical)
one of most serious forms of chemical injury