ch 4: altered cellular and tissue biology Flashcards
what is cellular adaptation? how long does it last? what does it do?
- a protective mechanism
- only temporary
- enhances cell function
5 types of cellular adaptation? what happens with each?
- atrophy
- hypertrophy
- hyperplasia
- metaplasia
- dysplasia
what are the two types of atrophy?
- physiologic atrophy
- pathologic atrophy
when is physiology atrophy common?
during early development
where does pathologic atrophy occur? what does it depend on?
- can be local or generalized
- depends on underlying cause
what is disuse atrophy?
decreases in workload
what is denervation atrophy?
loss of innervation
what is ischemic atrophy?
lack of blood supply
what is senile atrophy?
aging
what are the atrophic changes?
- decreased mitochondria
- increased protein catabolism
- increased autophagic vacuoles
what cells are most often affected by atrophy?
- skeletal muscle
- heart
- brain
- sex organs
what is another name for protein catabolism?
degradation
what is physiology hypertrophy commonly associated with?
exercise
what is pathologic hypertrophy induced by?
workload requirments
what are the 2 types of signals for hypertrophy?
- mechanical signals: stretching
- trophic signals: growth factors, hormones, and vasoactive agents
what does hypertrophy increase?
- functional tissue mass
- organelles
- protein synthesis
- demand on cell due to increase workload
what cells are most often affected by hypertrophy?
- non-dividing cells
- skeletal muscles
- myocardium
- kidney cells
what are the two types of physiologic hyperplasia?
- compensatory: regeneration of organ tissue
- hormonal: estrogen dependent organs
what are the common cells of compensatory physiologic hyperplasia?
- liver
- epidermal layers
- interstitial epithelia
- bone marrow cells
- fibroblasts
what are the common cells of hormonal physiologic hyperplasia?
- mammary
- uterine
when can hormonal physiologic hyperplasia often occur in conjunction with hypertrophy?
pregnancy
what is pathologic hyperplasia? what tissue is commonly involved?
- abnormal proliferation in response to excessive hormonal stimuli or growth factor
- endometrium
what are the increased hyperplasia changes?
- mitotic activity
- DNA synthesis
- production of growth factors in dividing cells
what is metaplasia?
REVERSIBLE replacement of one mature cell type by another less mature cell type
what are the characteristics of metaplasia?
- reprogramming of stem cells or undifferentiated cells
- occurs in response to chronic irritation and inflammation
- common with smoking
when is metaplasia reversible?
if causative factor is removed before a cancer develops
what is dysplasia?
- deranged cellular growth
- abnormal changes in size, shape, type or organization of mature cells
what is atypical hyperplasia?
not true adaptive change
mechanism of dysplasia?
- chronic or severe irritation or inflammation
- potentially reversible if improper stimuli removed
- often leading to cancer
- can be mild, moderate, or severe
what are the common tissues associated with dysplasia?
- uterine
- cervix
- breast tissue
what is neoplasia?
- altered cell differentiation or growth
- aka cancer
what is atrophy?
decreased cell size
what is hypertrophy?
increased cell size
what is hyperplasia?
increased cell number
what is apoptosis?
cellular self-destruction for elimination of unwanted cell populations
what is autophagy?
eating one self
what is cellular injury?
unable to maintain homeostasis in the face of injurious stimuli
what is the mechanism of hypoxia?
- reversibility
- depends on duration, degree of deprivation, and metabolic needs of cell
- sudden onset leads to anoxia (irreversible)
- gradual onset is reversible and adaptation occurs, usually atrophy
what are the 6 main categories of cell injury?
- hypoxic injury
- free radicals and reactive oxygen species
- chemical injury
- unintentional and intentional injury
- infectious injury
- immunologic and inflammatory injury
what is hypoxic injury? what are the four types?
- lack of sufficient oxygen
- single most common cause of cellular injury
- hypoxemia
- ischemia
- anemia
- histotoxic
what is hypoxemia? what can cause this?
- insufficient oxygen reaching blood cells
- decrease amounts of oxygen in the air
- deficiency of respiratory system
- occluded airway
- emphysema
what is ischemia? what is it the most common cause of? what causes this?
- failure to transport o2 due to reduced blood supply
- cause of hypoxia
- blockage in delivery of blood to the cells; MI, stroke, arteriosclerosis
- cardiovascular disease; congestive heart failure
what is anemia? what is it caused by?
- reduction of o2 carrying capacity of blood
- decrease in number RBC
- loss of hemoglobin or hemoglobin function
what is histotoxic?
impaired use of o2 by cell
what is the mechanism of hypoxia?
- reperfusion injury restoration of o2 may cause additional injury
- result of formation of highly reactive oxygen interemediates
- may result in cell necrosis bc cell has become adapted to lowered oxygen state
what are free radicals and reactive o2 species injury?
- atom or group of atoms with unpaired electrons
- highly reactive
- low chemical specificity to it can bond to molecules in membranes and nucleic acids
- microwaves and tvs
what are the 4 main injury mechanisms for free radicals?
- lipid peroxidation
- fragmentation of polypeptide chains
- alteration of DNA by breakage of single strands
- damaging mitochondria, liberating calcium
what is a cellular injury? what is the common injury target?
- toxic substance reacts with the cellular membrane
- creates increases permeability
- blocks enzymatic pathways
- liver
what are some examples of chemical injury?
- lead exposure
- carbon monoxide
- alcoholism
- marijuana
what are some systems that are injured from lead exposure poisoning?
- nervous system
- hematopoietic system
- kidneys or the urologic system
what are some symptoms of carbon monoxide poisoning?
- headache
- giddiness
- tinnitus
- chest pain
- confusion
- nausea
- weakness
- vomiting
what are some symptoms of alcoholism?
- pancreatitis
- liver failure
what is anthropogenic?
causes from human activity releasing mercury to the air
what are symptoms and signs of fetal alcohol syndrome?
- growth retardation
- facial anomalies
- cognitive impairment
- ocular malformation
what is an asphyxial injury?
caused by failure of cells to receive or use oxygen
what is suffocation?
oxygen failing to reach blood
what kind of wound has a high risk for infection?
puncture wound
what is a contusion? what is it most commonly associated with?
- bruise
- bleeding into skin or underlying tissue
- skull fracture
what is a laceration?
- tear or rip resulting when tensile strength of skin or tissue is exceeded
- irregular edges
what is a fracture?
blunt force blows or impacts that can cause bone to break or shatter
what is a incised wound?
- longer than it is deep
- significant external bleeding
- distinct edges
- superficial lacerations
what is a stab wound?
penetrating sharp force injury that is deeper than it is long
what is a puncture wound?
- instruments or objects with sharp points but without a sharp edge produce puncture wounds
- stepping on a nail
- pricked with a needle
what is a chopping wound?
- heavy, edged instruments produce wounds with a combination of sharp and blunt force characteristics
- axes, hatchets, propeller blades
what is a contact range entrance wound?
- gun is held so the muzzle presses on skin surface
- searing of edges of wound from flame
- soot or smoke on edges of wound
- severe tearing and disruption of tissue
what is a intermediate range entrance wound? what is tattooing and stippling?
- surrounded by gunpowder
- tattooing is from the burning from gunpowder
- stippling is when is does not break the skin
what is an indeterminate range entrance wound?
-when flame, soot, or gunpowder does not reach the skins surface but the bullet does
what is an exit wound?
-on the opposite side from the entrance wound
what is an entrance wound?
-on the side where the bullet is shot at
what is the most common manifestation?
inflammation
what is an immunologic and inflammatory injury?
phagocytosis and inflammation
what can manefestations cause a cell to do?
not function normally
what does cellular swelling cause? what is it usually due to?
- edema
- hypoxic injury
what is oncosis?
cell death as a result of failure of the sodium potassium pump
what level is excess bilirubin the cells?
1.5-2 mg/dl of plasma
what can excess bilirubin the blood do to the cells?
damage the membranes because of the lipid is lipid soluble
what is necrosis?
not organized cell death
what is apoptosis?
organized cell death
what are the different types of necrosis?
- coagulative
- fat
- liquefactive
- caseous
- gangrene
what is fat necrosis? examples?
- cell death of the muscular tissues
- post heart attack
- hypoxic injury
what is coagulative necrosis? examples?
- action of lipases
- liver, pancreas, breasts
what is liquefactative necrosis? examples?
- liquid
- bacterial infection
- strokes
- glial cells
- e coli
what is caseous necrosis? examples?
- combination of coagulative and liquefactative
- TB
- inflammation response
what are the different types of gangrene necrosis?
- dry
- wet
- gas
what is gas gangrene?
- HAI
- poor wound care
- result of bacterial infection
- smelly
- rotting flesh
what is dry gangrene?
- most common
- diabetics lose appendages
- usually due to interference with arterial blood supply
what is wet gangrene?
-neutrophils invade site
what is pathologic apoptosis?
cancer
