cellular injury and repair Flashcards
why does cell injury happen?
result of stress where cels can no longer adapt or also when they are exposed to damaging chemicals
what can injury result in the reduced production of?
ATP, which causes sodium potassium pumps to be effected and damaged which means they can no longer function.
what does this result in?
increased amount of water entering the cells, which in turn causes swelling in the effected area
what is hyperplasia
when cells increase as a resuly of increases mitosis, this isnt cancer but can become it
what is hypertrophy
when cells increase in cell size, if there is enough then the whole organ will increase in size
what is atrophy
the opposite of hypertrophy, where cells decrease in size and the whole organ can decrease in size
what is bruising caused by?
it is a hype of hematoma, localised bleeding of the tissue and occurs when capillaries are damaged due to trauma
what is metaplasia
when cells of a certain type are replaced by another type which may be less differentiated.
what is necrosis
chaotic cell death
what is apoptosis
programmed cell death
what is apoptosis caused by
caused by stimuli eg killer t cell signalling, this is an immune response to cancer or viral infections
or tissue shedding and turn over.
what are things that cause necrosis
caused by disturbance to cell membranes, eg electrical shocks, blunt trauma, radiation trauma, temperature extremes. can also happen when there is oxygen stress, which prevents respiration
and infectious toxins
does apoptosis need ATP to occur
yes it does
does necrosis ned atp to occur
no it occurs when atp is lacking
how can apoptisis be useful?
it is programmed to happen, helps to replace cells in active tissue, protective against cancer cells.
what happens after cell death in necrosis
explosion release lysomes, neighbouring cells are damaged leading to further cell death
what are 3 responses to tissue injury
inflammation,blood clotting,regeneration
how does blood clotting occur
happens when there is damage to blood vessels,thromboplasin is released by platelets,this catalyses and makes a enxyme called thrombin.
this creates fibrin fibres that form a mesh and attach to platelets, this the is a blood clot.
what is inflammation
it is where tissue fluid is accumulated when damage has happened to capillaries, plasma proteins leak out of tissue fluid followed by water.
can cause heat and pain also
what is ischemia
occurs when there is not enough blood supply to a part of the body
what is hypoxia
low oxygen in the bloodw
what is anoxia
no oxygen in the blood at all
what can be the cause of ischemia, hypoxia and anoxia
blood clots that have formed in the arteries, or narrowing of the arteries, stroke, can lead to necrosis of cells in that area
what is chronic diabetes
condition where the body no longer controls blood sugar levels, can lead to atrophy
