cell injury + inflammation Flashcards
lecture 1
list some factors influencing healing
- physiological variables
- general health of individual
- comorbid presence (diabetes, alzheimer’s, incontinence, cancer)
- type of tissue
causes of cell injuries
- Ischemia
- Infectious Agents
- Immune Reactions
- Genetic Factors
- Nutritional Factors
- Physical Factors
- Chemical Factors
- Psychosocial Factors
Ischemia - Cell Injury
when blood flow is insufficient enough to maintain cell function and keep homeostasis, leading to apoxia [total reduction of o2] or hypoxia [partial reduction]
what happens as a result of hypoxia or anoxia [ischemia]?
insufficient oxygen to the body limits blood flow and o2 supply, leading to loss of aerobic metabolism and reduction in ATP synthesis
*accumulation of ions and fluids ——-> swelling of cells —> compromising function
causes of ischemia
- atherosclerosis
- suffocation
- pneumonia
- thrombus (clot)
- anemia (inadequate transport of O2]
- CO poisoning
infectious agents [cell injury]
which one is more common?
how do viruses kill?
- bacteria is the most common infectious agent, they release exotoxins
- viruses kill through cytopathic and indirect cytopathic effects
chemical reactions - infectious diseases
methods + define
defined: substances that injure cells
methods:
- directly (ex: mercury)
- indirect: substances that require metabolic transformation into toxic agent (ex: drugs)
Free Radicals (chemical factors)
- “unstable o2 molecules” - an O2 loses one of their electrons
- overproduction can lead to cell injury and death AKA oxidative stress (factors in 90% of diseases)
Antioxidants
foods that contain antioxidants
exogenous antioxidants
endogenous antioxidants
body responses to neutralize free radicals
exogenous: vitamin c, lycopene
endogenous: enzymes
causes of free radical formation
- UV rays
- pollutants
- drug overdose
- prolonged exercise
Genetic Factors - Cell Injury
alterations to the structure or number of chromosomes can induce abnormalities
single mutations defined & example
can cause changes in the amount and function of proteins
ex: sickle-cell anemia
environment + multiple gene mutation examples
hypertension
diabetes 2
mechanical factors can lead to…
typical tissues response to physical stress includes decreased stress tolerance and increased stress tolerance
causes of tissue injury - mechanical factors
- repeated episodes of magnitude force
- slow degradation of tissue tolerance
- low loads sustained over long periods
nutritional factors - kwashiorkor
protein malnutrition
extremes of physical factors
- electricity
- temperature
- radiation
physical factors
blunt or penetrating trauma, survivors may die later due to infections or organ failure
what is a prime target for age-related changes?
mitochondrial DNA
lipofuscin - cellular aging
aging-pigment granule (lipid) is higher concentrations in older cells
types of cellular aging
- reversible
- irreversible
adaptations of cell injury
- hyperplasia
- dysplasia
- hypertrophy
- atrophy
- metaplasia
hyperplasia
increased number of cells
dysplasia
increase in number of cells and change of morphology, loss of histologic organization
atrophy
decrease in size of cell
hypertrophy
ex:
increase in cell size
ex: Left ventricle bc of heart cells and striated cells
metaplasia
ex:
change in cell morphology, smokers have this :(
necrosis features
nucleus:
plasma membrane:
cellular contents:
inflammation?
nucleus: - pyknosis, kyorrhexis, karyolysis
plasma membrane: disrupted
cellular contents: may leak out
inflammation? YES
pyknosis
clumping of cells
karyorrhexis
fragmentation
karyolysis
dissolution
acute inflammation ERYTHMA
vasodilation and increased blood flow
heat
vasodilation and increased blood flow
edema
fluid and cells from cells leaking into extravascular spaces
inflammation purpose
removal of injurious agent, removal of cellular debris, and initiation of healing process
characteristics of acute inflamation
- vasodilation
- increased capillary permeability
- clotting of fluid
- migration of leukocytes
vasodilation leads to…
increased blood flow, causing redness and resultant heat [erythema]
increased capillary permeability permits
- passage of plasma proteins into extravascular space (EDEMA)
- higher concentration of RBCs and slower blood flow
factors affecting blood flow
- histamine
- seratonin
- platelet activating factor
- cytokines
- plasma protein systems
edema
fluid and cells from blood vessels leaking into extravascular spaces
effusion
escape of a fluid into anatomical space
exudation: escape of fluid into fluid cavity
transudate: fluid with low protein
sanguineous appearance
hemorraghic, bright and red
serosanguinous appearance
blood tinged yellow or pink
serous appearance
yellow with albumins
purulent
with pus
catarrhal
with pus
leukocyte accumulation and lifespan
they try to eliminate injurious substance, have 24 hour lifespan RIP
what indicates an active inflammatory reaction?
leukocytosis - increased number of WBC
leukopenia
decreased number of WBCs, indicator of grave prognosis eg. sepsis
histamine - blood flow chemical mediator
released by:
allows?
released by MAST CELLS
vasodilator **
increase vessel permeability, allows fluids and blood cells to exit into interstitial spaces
platelet-activating factor
prostaglandins, leukotrienes
come from lipids, increase leukocytes and activities of mediators
ex: allergies and asthma
cytokines
IL-1
TNF causes
structure? omg
structure: POLYPEPTIDES
IL-1: fver
TNF: induce IL-1
autocrine + paracrine
plasma protein systems:
function
3 factors
create breakdown of proteins
blood clotting
1. blood coagulation
2. kinin enzymatic system
3. complement system
kinin: bradykinin
causes dilation + pain
hegman factor:
plasma protein that activates clotting
hallmark of chronic inflammation is the accumulation of inflammation
plasma cells
macrophages
lymphocytes
what is secreted by fibroblasts during early tissue repair
proteoglycans
what are the phases of leukocyte accumulation
- margination
- adhesion of molecules
3> diapedesis
4> chemotaxis
prednisONE
corticosteroids, anti-inflammatory
celeCOXIB
cyclooxygenase COX2
immunosuppresant
