Chapter 4 - Altered Cellular and Tissue Biology Flashcards
Why does cellular injury occur?
cell unable to maintain homeostasis
two types of cell injury?
reversible (cell recover) & irreversible (cell die)
2 things that occur during cellular adaptation?
physiological - adaptive
pathogenic - causes disease
What are the five types of cellular adaptation? Explain each of them.
atrophy - decrease in cellular size
hypertrophy - increase in cellular size
hyperplasia - increase in number of cells
metaplasia - replacement of one cell type with another
dysplasia- deranged cellular growth.
what are the four cellular injury mechanisms?
hypoxic injury, free radicals and ROS, chemical injury, chemical agents including meds
what is the common cause of cellular injury?
hypoxic injury
what is ischemia? And what causes ischemia?
inadequate blood supply; hypoxia
what occurs in hypoxic injury?
reduced O2 production in mitochondria, therefore there is reduced production of ATP (1), meaning there is reduction of cellular energy.
(2)increase accumulation of H+ in mito = breakdown in mitochondrial membrane = increase in intracellular H+ = loss of membrane potential =necrosis.
what is ischemia reperfusion injury?
additional injury caused by restoration of blood flow and O2
what are the 3 mechanisms of ischemia reperfusion injury?
inflammation, oxidative stress, increased intracellular Ca
what are the cellular responses of ischemia-reperfusion injury?
decrease in ATP, leads to failure of Na-K pump and Na-Ca exchange (1) & cellular shrinking and swelling (2)
what are free radicals?
missing an electron, so they attack healthy atom to obtain a replacement electron.
what is the by-products of normal metabolism & created with metabolism of O2?
reactive oxygen species (ROS).
what causes oxidative stress?
not producing enough antioxidants to break down current free radicals (1)
major role in chronic and degenerative ailments (2)
too many free radicals = oxidative stress (cellular stress) = damage to cells)
what prevents damage to cell?
antioxidants
what causes free radicals and ROS
lipid peroxidation (1), alteration of proteins (2), alteration of DNA
what are xenobiotics?
substances foreign to body
some examples of xenobiotics?
lead, carbon monoxide, ethanol, mercury
where is the major injury ethanol impose?
liver
where is ethanol absorbed?
stomach
what shaped is the effect of alcohol consumption?
J-shaped
what is the mechanism for light to moderate drinkers?
low LDL levels, decreased b.p and decreased atherosclerosis
what xenobiotics recognized as a global threat to human and envrionmental health
mercury
this xenobiotics is the most common overexposure found in industry?
lead
what xenobiotics is odorless, colorless and nonirritating?
CO
CO ultimately causes hypoxic injury due to ____; CO attaches to mitochondria with a ______
O2 deprivation; higher affinity than O2
what is the leading cause of child poisonings?
medications
what are some hypersensitivity rxns from medications?
range from mild skin rashes to immune-mediated organ failure
activation of ___ metabolites is a drawback from chem agents including meds
toxic
how does chemicals and meds apply direct damage?
they injure cells by combining directly with critical molecular substances (1) & chemotherapeutic meds/drugs of abuse
what is asphyxiation?
failure of cells to receive or use O2
what causes asphyxiation?
suffocation: systemic hypoxia/ no air exchange (1), strangulation: compression/ closure of airway/ causes cerebral hypoxia (2) & drowning: fluid fill lungs/ no O2 exchange (3)
what chem preven O2 delivery to cell or its utilization?
CO and cyanide
what chem binds to Hb in same position as O2? treatment?
CO; hyberbaric chamber
what chemical blocks utilization of O2 at electron transport chain? cause of death?
cyanide; cardiac arrest
what is contusion?
crushing injury to muscle; mild = bruising
laceration?
irregular cut from tearing/ irregular edges
incision?
sharp strait wound
fracture?
broken or shattered bones
incised wound?
wound is longer than it is deep
stab wound?
wound is longer than it is deep
puncture wound?
sharp point but not sharp edges
what is infectious injury?
invasion of pathogen.
what might occur from disease-producing potential of pathogen infection?
invasion and destruction (1), toxin production (2) & production of hyper immune rxn (3)
what are the 3 types of cellular death?
necrosis, apoptosis, autophagy
which cell death occurs as a normal controlled part of an organism’s growth and development?
apoptosis
this is the consumption of a cell’s own contents for fuel to oppose starvation and certain diseases
autophagy – i.e., self-consumption
the swelling and bursting of cell membrane & due to disease, injury, failure of blood supply?
necrosis.
Necrosis occurs at _____
cellular level
what is the cause of coagulative necrosis?
ischemia or infarction – obstruction of blood supply causing death of cell
what organs linked to coagulative necrosis?
kidney and heart
till when ischemic cells can be revived if O2 is supplied?
20 minutes
Coagulation is a result of protein _____
denaturation
what type of necrosis is due to dead tissue resemble clumped cheese?
caseous necrosis
what organ does caseous necrosis affect?
lungs
what causes caseous necrosis?
tuberculous
what is the danger imposed by caseous necrosis?
dead cell enveloped by other cells/ increased mass= decreased lung space
this type of necrosis is due cause by ischemic injury to neurons and glia cells & infarction?
liquefactive necrosis
organ affected by liquefactive necrosis?
brain
what is the bacterial infection in liquefactive necrosis?
streptococci/ E.coli
this necrosis is usually harmless and often left alone and let body absorb it?
fatty necrosis
organ affected of fatty necrosis?
breasts and abdominal organs
in fatty necrosis, action of _____ occurs?
lipases
this is severe hypoxic injury often to major arteries in lower leg?
gangrenous necrosis
gangrenous necrosis is susceptible for what bacterial growth?
anaerobic bacteria
this type of necrosis is due to clostridium speices infection?
gas gangrene
As clostridium enter wound in gas gangrene, what does it produce?
gas
how is gas gangrene fatal?
if it enters blood and diminishes O2- carrying capacity of RBC
what is the process of cell death due to swelling?
oncosis
what happens in aging?
cellular aging, tissue and systemic aging and frailty
what is cellular aging
atrophy, decreased function and loss of cells
what happens in tissue and systemic aging
progressive stiffeness and rigidity
what is sarcopenia
progressive/ generalized loss of skeletal muscle mass and strength
what happens in frailty
mobility, balance, muscle strength, motor activity, cognition, nutrition, endurance, falls, fractures and bone density
