cell injury and cell death Flashcards
cellular responses to stress and injury includes:
1- adaptive repossess as:
- atrophy
- hypertrophy
- hyperplasia
2- reverssible cell injury
3- irreversible cell injury = cell death
- necrosis
- apoptosis
—– refers to the decrease in size or number pff cells due to loss of cell substance which leads to :
—- workload
—– of innervention
- aging , fetal development , inadequate nutrition
- atrophy
- decrease
- loss
—- refers to the increase in the cell size and it involves — activation protein synthesis and production of ——
occurs in :
- hypertrophy
- gene
- organelles
- occurs in cells incapable of division so no new cells just large cells , physiologic and skeletal muscle w excersise and pathologic left ventricular hypertrophy in hypertension
—– increase in number of cells and the size of the organ which occurs in organs capable of —- and is often associated with —-
its also physiologic and :
and pathologic as:
its a —- process but fertile soil for —-
- hyperplasia
- cellular divison
- hypertrophy
- hormonal as breast uterus during pregnancy and compensatory as partial hepatecomy
- pathologic as excessive hormonal and growth factor as thyroid and endometrial hyperplasia
- controlled process
- cancer
—– refers to the reversible change in which one adult cell type is replaced by another adult cell type and it can be a precursor for —-
metaplasia , cancer
genetic reprogramming of stem cells as:
- ciggerate smoking - respiratory epithelium -> squamous
- Barrett’s oesophagus - squamous epithelium —> intestinal epitheliam
are examples of —–
metaplasia
causes of cell injury :
1- — deprivation as: hypoxia and ischaemia which is the — in blood flow , shock
2- —- agents as trauma thermal injury and radiation
3- —- agents as posion , drugs , pollutants
4- —- agents
5- —– reactions
6- —- defects
7- —— deficiency or excess
- o2
- decrease
- physical
- chemical
- infectious
- immunological reactions
- genetic defects
- nutritional
mechanism of cellular injury :
1- cellular responses depends on the —- as:
2- consequence depends on the — as:
- injury as type severity and duration
- cell as type state and adaptability
mechanism of cellular injury : - cell systems most vulnerable to injuries are :
1- mitochondria for aerobic respiration and ate-sythesis
2- cell membrane
3- synthetic apparatus protein and enzymes
4- cytoskeleton
- genetic apparatus aka dna
mechanisms associated w injuries :
1-inhibition of —– which leads to atp depletionnn
2- —– damage
3- generation of —– species aka —-
4- defects in ——-
5- disruption of —–
6- damage to —
-aerobic respiration
- mitochondrial
- oxygen species as free radicals
- membrane permibilty aka membrane damage
- calcium homeostasis aka calcium influx
- dna and proteins
- increased anaerobic glycolysis
- reduced sodium pump = accumulation of sodium n water
- reduced calcium pump
- decreased atp
- decrease phosolipids
-nuclear chromatin damage - disruption of membrane and cytoskeletal proteins
are all mechanims for:
reversible injury due to decreased phosphorylation within the mitochondria
—- injury is when the mitochondria changes , extensive plasma membrane damage and injury to the lysosomal membrane which activates the enzymes and degrades damaged cells and the release of enzymes damage the surrounding cells
irreversible injury
—- highly unstable and reactive chemical species w a single unpaired electrons examples :
▪ Superoxide O2
▪ Hydrogen peroxide H2O2
▪ Hydroxyl ion OH-
free radicals
important:
the morphological changes associated w reversible injury:
- Cellular swelling (hydropic change, vacuolar
degeneration) - Ultra structural changes
▪ Plasma membrane alteration-blebbing
▪ Loss of microvilli
▪ Mitochondrial swelling
▪ Dilation of endoplasmic reticulum with detachment of
ribosomes
▪ Nuclear alterations
important:
morphological changes associated w irreversible injury:
Membrane damage:
▪ Plasma membrane → enzymes released (e.g.
troponin, amylase)
▪ Mitochondrial membrane
▪ Lysosome (lytic enzymes)
