Lecture 2 - Altered Cell Biology Flashcards
What is neoplasia?
The formation or presence of a new, abnormal growth or tissue
What are some normal cell adaptations?
callouses, tanning, uterine/mammary gland changes, larger adrenal gland during stress
What are some abnormal cell adaptations?
cell death by burn
mole
wart
cancer
Definitions
Atrophy
Hypertrophy
Hyperplasia
normal cell changes
smaller cells
larger cells
more cells
Definitions
Metaplasia
Dysplasia
abnormal cell changes
replacement of one cell type with another cell type
loss of normal organization of cells. often pre-cancer condition
Factors that can determine extent of cell damage
genetics age gender race nutrition others
Lack of oxygen to tissues
hypoxia
hypoxia is caused by…
decreased blood flow
blockage of vessels
heart failure
hypoxemia (low oxygen in blood)
hypoxia causes…
switch from aerobic to anaerobic metabolism
high lactic acid
low ATP
decreased adenosine inside cells
lack of ATP in cells causes…
decreased activity of ion pumps cell swelling (osmosis due to ions)
What is the tissue damage associated with hypoxia?
ischemia
Full manifestation of what takes 24-48 hours
ischemia
Why is rapid restoration of blood flow bad?
it results in excess oxygen delivery to the tissue, which generates ROS (reactive oxygen species) that cause oxidation of lipids and proteins
Called reperfusion injury
What does alcohol target to damage?
liver and brain
what do barbiturates target to damage?
brain and kidney
what does lead target to damage?
brain and RBC’s
where do endotoxins come from?
Also called lipopolysaccharides (LPS), are part of outer coat of GRAM-NEGATIVE bacteria
they are non-specific (affect many tissues)
what do endotoxins do?
increase release of cytokines
what do cytokines do?
stimulate immune/inflammation
increase body temp
malaise
vaso-dilation
where do exotoxins come from?
gram-positive bacteria
they are very specific - only affect single pathway or specific tissue
What is bacteremia and what does it do?
growth of bacteria in the blood
destroys blood cells
causes large inc of cytokines
can cause rapid death
DNA viruses
inject DNA
use cell to make mRNA, then viral proteins
cellular components are transformed into things to make new viruses
RNA viruses
inject RNA
RNA is reverse transcribed into viral DNA
DNA transcribed into viral mRNA then proteins
eventually utilized to make new viruses
What are good targets for radiation?
large molecules (especially DNA)
What are some rapidly growing cells in the body?
cells of: gastrointestinal fetus bone marrow lymph node skin hair
What will mild cold cause? (temp)
decreased ATP
therefore, effects of hypoxia
What will severe cold cause? (temp)
ice crystals which puncture and destroy cell membranes
What is hemosiderin?
a storage form of iron
What causes gangrene?
lack of oxygen
How is gangrene manifest?
dry: when oxygen cut off slowly. dry. little inflammation
wet: found in areas of high blood flow. when oxygen supply cut off quickly. red and inflamed
gas: infection in area of wet gangrene. smells terrible. gas pockets. large cytokines, death rapid
What causes gas gangrene?
Clostridium infection of dead tissues in are of wet gangrene
How to treat gangrene?
keep sterile
remove dead tissue
antibiotics
hyperbaric chamber (high oxygen)
