adapt (survival and continued function), and alteration depends on nature of stressor/injury

die if stress overwhelms the cells or adaptations fail

blood cells

liver cells

others

neurons

nephrons

heart muscle

adaptation

cell injury

neoplasia

cell and tissue aging

cell death

cells adapt to their environment to escape and protect themselves from injury

atrophy

hypertrophy

hyplasia

dysplasia

metaplasia

from hypoxia, free radicals, chemicals, trauma, infection, or effects of immune system or inflammation

can be reversible or irreversible

an adaptation where there is a decrease in cellular size

happens to pts in hospital after not moving around-can be rebuilt

incerase in size of cells and consequently increse in size of affected organ

hypertrophy of left ventricle in left-sided heart failure-cells increease in size from having to work harder

change in muscle size with weight training

incerase in the number of cells resulting from increased rate of cellular division

removal of part of the liver leads to hyperplasia of remaining cells to compensate

breats enlargement durng pregnancy

reversible replacement of one type of cell or tissue for another usually less functional cell

if stimulus for metaplasia is stiopped, tissue mey revert ot normal, but if not removed, dysplasia or neoplasia may result

when cartilage is replaced by bone

barretts' esophagus from GERD

abnormal change in cell so not true adaptation

also called hyperplasia

may be a change in size, shape, and organization in cell

often doesn't function normally

may develop into cancerous or neoplastic changes in cells

cervical dysplasia on PAP smear, a precursor to cancer

physocal agents

radiation

chemical injury

mechanical forces (tears to tissue and blood vessels)

temperature extremes

high temps: heat strokes, burns

low temps:decreased blood flow, increased viscosity, frostbite, ice crystal formation

electrical forces (lightning, high voltage wires)

radiation

increases risk of cancer

xrays are a form

radiation is the use of high (but less than lethal) doses of radiation usually to destroy cancer cells

CT scan is controversial form of radiation-helpful but should be limited

many think no amount is safe; weigh harm vs benefit

strength of source

proximity to the source

length of exposure

presence of protective or repair mechanisms (like antioxidants)

genetic susceptability

bystander effect (gentic instability produced in non-radiated cells)

can lead to gene mutations, release of tumor necrosis factor alpha, inflammatory response and release of free radicals, squamaous cell and basal cell carcinoma, all r/t cumulative exposure

increasing with depletion of ozone layer

typically found on body parts exposed to sunlight

increase in melanoma rates

lighter skin, hair and eyes are risk factors

melanoma thought ot be r/t:

episodes of intense sunburn

positive family history

light skin and tendancy to freckle

potential damamge from thermal injury

possibly carcinogenic due to mutations

controversial/conflicting reports

includes non-ionizing like : microwaves, radar, radio/TV waves, flourescent lights, electricity, cell phones

don't live next to high-voltage power stations

limit cell phone use in children

keep cell phone away from body when not in use

use speakerphone/texting

cell phone data not conclusive

chemical injury

usually begins with damage to cell membrane and increase in permeability

minute amount of substances like cyanide result in rapid death

chronic exposure to substances like air pollution lead to gradual injury

heavy metal injestion = lead poisoning

serous damage to nervous system, even in small amounts

children are especially susceptible

fetal exposure should be avoided (harms development of nervous sytem)

laws have been enacted to decrease lead in gasoline and paint

odorless, colorless gas from incomplete combustion of fuel

chemical, but mainly produces hypoxic injury

CO affinity for hemoglobin is 300x greater than that of O2

binds with hemoglobiun so O2 can't, cells die

dizziness

nausea

cherry red lips