Cell Injury and Fate Flashcards
What happens to cells that experience increase in demand beyond elastic point
When the cells cannot meet the demand, cell injury or cell death occurs
What is sublethal cell injury
Damage to the cell that does not directly kill the cell. It can be reversible and repaired or result in death with more injurious stimuli
What are the 8 causes of cell injury
Oxygen deprivation, chemical agents, infectious agents, immunological responses, genetic defects, nutritional imbalance, physical agents and ageing
Why what three things is the amount of cell injury induced by injurious stimulus determined
The type of injury, the duration of the injurious stimulus and the severity of the injurious stimulus
What two things does the consequence of injurious stimulus depend on
Depends on the type of cell and the status of the cell, for example replicating cell
Which four intracellular systems are particularly vulnerable to cell injury
Cell membrane integrity dependent on electrochemical equilibrium, ATP generation dependent on oxygen, protein synthesis dependent on ribosome integrity and genetic apparatus dependent on DNA stability
What is lost before morphological changes can be seen in cells
Cell function is lost before morphological changes indicative of cell death can be seen
What is atrophy and in what two diseases may this be seen often
Atrophy is the shrinkage of cells in size by loss of cell volume, which is seen dementia and after denervation of muscle tissue
What is hypertrophy and what causes it
Hypertrophy is an increase in size of cells, which can be caused by an increased physiological requirement or hormonal stimulation
Is muscle gain due to hypertrophy or hyperplasia
Muscle gain is largely due to hypertrophy and not hyperplasia
What is an example of physiological and pathological hypertrophy
Physiological hypertrophy occurs in the uterus during pregnancy, while hypertension can lead to cardiac muscle hypertrophy to meet the pathologically increased demand
What is hyperplasia and what causes it
Hyperplasia is an increase in the number of cells in an organ, which can be both physiological and pathological and occurs under hormonal stimulation
What is an example of physiological and pathological hyperplasia
An example of physiological hyperplasia is the oestrogen stimulated growth of the uterine endometrium, pathological example are cancers
What is metaplasia and what is an example in the cervix and oesophagus
Metaplasia is a reversible change in the morphology of cells which can occur due to environmental changes. In the cervix during pregnancy as the cervix expands the end of the endocervical columnar epithelium changes to squamous epithelium due to acidity of vagina. Barret’s oesophagus can occur in people with acid reflux, the epithelium will experience much more acidity than in normally does and this can lead to oesophagal cells become columnar where they were squamous.
What is dysplasia and what is the distinction between pre-cancerous and cancerous cells
Dysplasia is when cells change morphilogically and genetically to noticeably abnormal cells but do not (yet) invade other tissues. In cancerous cells, these abnormal cells do invade surrounding tissues by migrating through the basement membrane of the tissue.
How can dysplastic cells often be distinguished in a histological examinations
Dysplastic cells often have an abnormal cytoplasm to nucleus ratio
What two histological changes can be seen in hepatocytes in degenerative alcoholic liver disease
Hepatocytes containing fatty granules and swelling of hepatocytes which is called ballooning degeneration
Which four types of changes in light microscopic histology are seen in irreversible cell injury
Coagulative necrosis, liquifactive necrosis, caseous necrosis, fat necrosis
What is an example of coagulative necrosis
In myocardial infarction coagulative necrosis of myocytes can occur
What type of necrosis is characteristic of brain damage
Liquefactive necrosis is characteristic of brain damage
What type of necrosis is characteristic of pulmonary tuberculosis
Caseous necrosis is characteristic of pulmonary tuberculosis
What type of necrosis is characteristic of acute pancreatitis
Fat necrosis is characteristic of acute pancreatitis
Why do histological examinations of acute pancreatitis contain blue regions
Calcium has been deposited by fatty acids binding to calcium and precipitate in the pancreatic tissue
What is difference between apoptosis and necrosis
Apoptosis is death of individual cells without inflammation, where in necrosis cells die and confluence and this induces inflammation
What is the difference in how cells die in apoptosis and necrosis
In apoptosis parts of the cell bud of with integral membrane in apoptotic bodies, whereas in necrosis the membrane loses integrity and cellular components leak out and enzymatic degradation occurs
What are three examples of physiological apoptosis in the body
Formation of the body structures during embryogenesis, deletion of self-reactive T cells in the thymus, hormone dependent physiological apoptosis for example in menstruation
How is the genome preserved through apoptosis
In response to mild injurious stimuli that irreversibly damage DNA, the cell undergoes apoptosis in a suicide pathway to ensure that proliferating cells only contain the appopriate genome
Why is ATP required for apoptosis
ATP is required to package cellular organelles and maintain membrane integrity of the apoptotic bodies to be cleared by macrophages
What is necroptosis and what is an example when this happens
Necroptosis is an energy dependent process of programmed cell death in which the dying cells bleb off but do induce an inflammatory response like in necrosis, often seen in viral infections
