Cell Injury & Fate Flashcards
What results in cell injury and death (overview) ?
The injurious stimulus to the normal cell such as decreasesin O2 or poison. Or the inability to adapt bc of stress etc. (heart can’t pump hard enough…)
What is lethal vs sublethal cell injury?
Lethal = cell death sublethal = produces injury that doesn't amount in cell death but it may progress to it or maybe reversible
What is an example of muscle cell injury?
ischaemia - death would be infarction
What is the acronym for cell injury causes?
A PIG COIN
What does A stand for in the acronym for cell injury?
Aging
What does PIG stand for in the acronym for cell injury?
Physical agents - trauma or radiation
Infectious Agents - virus, bacteria, multicellular parasites
Genetic defects - sickle cell..
What does COIN stand for in the cell injury in the acronym for cell injury?
Chemical agents - weed killer, drugs
Oxygen deprivation
Immunological deprivation - direct cell injury and those that can be triggered by infectious agents
Nutritional imbalance- too much or too little. - increase mass, diabetes … or not enough nutrients or proteins
What is a myocardial infarction caused by?
oxygen deprivation - cell death due to ischaemia
What does the cellular response to injurious stimuli depend on?
- Type of injury
- Duration - e.g. in MI you be able to lyse clot
- Severity
What do the consequences of an injurious stimulus depend on?
- Type of Cell - some cells are more resilient to injury e.g. bone, cartilage = low metabolic requirements and so can go on long w out o2 before cell death whereas brain = opposite
- Cell status - proliferating cells may be more subject to injury e.g. by cancer-causing injury
Which intracellular systems are particularly vulnerable to cell injury?
- Cell membrane integrity
- ATP generation
- Protein synthesis
- Genetic apparatus integrity
Why can multiple secondary effects rapidly occur?
the structural and biochemical components of a cell are high integrated… e.g. loss of ATP… cant maintain membrane etc
What are ways of adapting to cell injury?
Atrophy Hypertrophy Hyperplasia Metaplasia Dysplasia
What is atrophy?
Shrinkage of size of cell/organ
- by loss of cell substance.
e.g. neuralatrophy in dementia - gyri = thinner, sulci = thicker (gaps)
or muscle atrophy - whole muscle will get smaller
What is hypertrophy?
increase in size of cells
consequently an increase in size of organ
can be physiological ( process in normal healthy people, or pathological (part of a disease)
tends to increase mass
What is hypertrophy caused by?
increased functional demand or specific hormone stimulation
Example of physiological hypertrophy?
uterus in pregnancy (increases size)
Example of pathological hypertrophy that can also be physiological
larger myocyte - normal for athletes but can be in response to hypertension or valve abnormality (patho)