Altered Cells & Tissues (week 1 pt.2)

cellular adaptation

reversible, structural, or functional response to normal, pathological conditions, or environmental factors

atrophy

reduced cell volume/size causing the tissue or organ to become smaller

hypertrophy

inc. in cell volume/size causing the tissue or organ to enlarge (triggered by inc. in mechanical forces, trophic growth factors)

hyperplasia

increase rate of cell division lead to an inc # of cells causing the tissue or organ to be enlarged

dysplasia

atypical hyperplasia; inc. cell division, but their size, shape, & organization do not apear the same as normal tissue

metaplasia

replacement of 1 mature cell by another less mature cell type

cell injury leads to

injury of tissues and organs

reversible cell injury

cells will recover

irreversible cell injury

leads to cell death

what leads to irreversible cell inj?

increase concentration of stimulus, duration of stimulus (acute or chronic), and cell type

mild cell stress leads to

cell adaptation

cell adaptations

atrophy, hypertrophy, hyperplasia, metaplasia

moderate cell stress level leads to

reversible cell injury

severe/prolonged cell stress level leads to

irreversible cell injury

extreme cell stress level leads to

cell death

main cell injury causes (for this class)

toxic chemicals, infectious agents, oxidative stress, physical trauma

biochemical mechanisms of cell injury

ATP depletion, electrolyte imbalances, etc.

hypoxia

inadequate oxygen available to the cell

hypoxic hypoxia

not enough oxygen in the lungs

hypoxic hypoxia examples

low environmental oxygen, hypoventilation, diffusion impairment

hypemic/anemic hypoxia

inability to transport oxygen

hypemic/anemic hypoxia examples

CO poisoning, anemia, severe blood loss

stagnant/circulatory/ischemic hypoxia

poor blood flow

stagnant/circulatory/ischemic hypoxia examples

heart failure, coronary blockages

histotoxic hypoxia

tissues can’t utilize oxygen

histotoxic hypoxia examples

cyanide poisoning, toxins, etc.

ischemia

reduced blood flow to 1 or more areas of the body

ischemia effects

reduced oxygen delivery (hypoxia), reduced nutrient delivery, impaired waste removal

reperfusion injury

restoration of blood flow that worsens cell injury

reperfusion injury causes

oxidative stress, calcium overload, inflammation

oxidative stress

imbalance btwn free radicals & the antioxidant system often caused by ROS

reperfusion injury examples

MI, organ transplant, ischemic stroke

free radicals

atoms with an unpaired electron in their outer orbit

dif. types of chemical cell injury causes (for this class)

ethanol, lead, carbon monoxide

ethanol main cell injury effect

steatosis (fat accumulation)

lead poisoning toxicity affects

CNS & PNS

CO poisoning decreases

oxygen carrying capacity of Hb leading to hypoxia

immunologic/inflammation cell inj.

autoimmune response or overzealous response to pathogen

physical agents (cell inj.)

temperature extremes, changes in atmospheric pressure, ionizing radiation, mechanical stresses

ionizing radiation (cell inj.)

any form of radiation capable of removing orbital electrons from atoms

ionizing radiation examples

X-rays, gamma rays, alpha and beta particles

ionizing radiation effects can be

• direct

• indirect

indirect radiation types

horizontal, vertical

vertical (indirect radiation)

DNA damage (from radiation) can effect future daughter cells

horizontal (indirect radiation effects)

cells not directly in the radiation field can be damaged due to free radicals released from the affected cell

horizontal effects are aka

bystander effects

cell injury can lead to the accumulation of substances known as

infiltrations

2 types of abnormal infiltrations

endogenous, exogenous

endogenous abnormal infitrations

products of abnormal metabolism/synthesis

exogenous abnormal infiltrations

infectious agents, minerals

there are ___ types of infiltration mechanisms

4

infiltration mechanisms deal with ____ of abnormal substances in a cell or ____ removal of removal of infiltrations in a cell

accumalation, insufficient

the 2 main types of cell death are

necrosis and apoptosis

necrosis

cell death that can lead to cell injury/death to nearby cells & induces inflammatory changes

apoptosis

programmed cell death, no inflammatory changes, does not lead to the injury or death of nearby cells

coagulative necrosis

changes to protein albumin

organs effected by coagulative necrosis

kidneys, heart, and adrenal glands

liquefactive necrosis

hydrolitic enzymes form liquid-filled cyst or form pus

areas effected by liquefactive necrosis

neurons & glial cells in the brain

caseous necrosis

combo of coagulative & liquefactive necrosis, cheese-looking substance that is walled off

example of caseous necrosis

TB pulmonary inflammation

fatty necrosis

action of lipases

fatty necrosis occurs in

breast, pancreas, and other abdominal structures

gangrenous necrosis types

dry, wet, gas

gangrenous necrosis

death of a tissue due to inflammation and/or ischemia

dry gangrene

coagulative necrosis due to ischemia

wet gangrene

liquefactive necrosis due to bacterial infection

gas gangrene

caused by toxins produced by Clodstridium species