Flashcards in cell injury Deck (70)
define cell injury
injury to the smallest living unit in the body
what 4 factors does maintenance of cellular steady state involve.
1- preservation of genetic integrity
2- normal enzyme content.
3-intact membranes and transmembrane proteins.
4-Adequate supply of substrates and oxygen.
it a normal cell is put under stress what change will it undergo
if a normal cell is put under injurious stimulus then what process will take place
what 2 forms of cell injury are there
is irreversible cell injury takes place what happens to the cell
apoptosis and necrosis.
If cells are put under stress due to increased cellular activity they often adapt by undergoing what 2 processes.
if cell are put under stress due to decreased cellular activity they adapt by undergo in what process
metaplasia often occurs as a result of increased stress on a cell. what is metaplasia
change in cellular morphology
what changes morphologically occur in the cervix at puberty
at puberty the columnar cells replace some squamous cells at the squamouscoloumnar junction
What are the injurious stimuli which mean that a cell in unable to adapt and therefore becomes injured.
Others- immunological, lack of essential nutrients/vitamin, genetic disorders and ageing.
Lack of oxygen delivery to cells is known as
no oxygen delivery to cells is known as
Do loss of oxygen availability result in schema
Yes- if lest to long
No- cell can be reposed if condition causing hypoxia/annoxia is resolved within the given time frame.
what are the 2 main causes of physical trauma that cause cell injury
Mechanical trauma- disrupt cell structure, thrombosis, bullet shot through the head cause devascularisation.
Extremes of temperature- heat which denatures proteins and ice crystals.
what are the chemical causes which cause cell injury
alcohol, tobacco, drugs, poisons, environmental and occupational.
what are the 2 main modes of action of chemical agents in causing cellular injury
interference with cellular metabolism
what are the 2 types of bacterial toxins which result in cell injury
how do virus cause cell injury
Hijacking of cell machinery
and collateral damage by inflammation.
how does irradiation cause cello damage.
e.g. X-rays, radioactive particles
Generation of free radicals and direct damage to macromolecules
which parts of the body are very highly sensitive to irradiation
bone marrow, gonads, intestines- parts of the body with high turnover rate
which parts of the body are very lowly sensitive to irradiation
uterus, pancreas, adrenal
what are the main targets for cell injury
membrane integrity and function
surplus of what 2 chemicals can cause swelling (known as cloudy swelling) and what symptoms is this associated with.
Na+ and H20 surplus c- associated with hypoxia, but can be due to fever or damage due to toxins.
what is the consequence of ribosome detachment
decreased protein synthesis in the mitochondria.
what causes decreased pH in injured cells
low glycogen and high lactic acid.
low pH results in less lipids being packaged and hence they build up- fatty change.
define a free radical
Highly reactive ions or molecules with single unpaired electron in outer orbital e.g. oxygen free radicals
what can cause membrane defects
bacterial toxins, viral proteins, complement, cytolytic lymphocytes, and various physical and chemical agents
what detoxifies free radicals
superoxide dismutase and antioxidants.