Cell Injury & Fate Flashcards
What are the mechanisms and consequences of cell injury dependant on?
Type of injury, duration, severity, stage in cell cycle and type of cell.
What is atrophy? Examples when this occurs?
The shrinkage of cells or organ by loss of cell substance, occurs with dementia and nerve damage.
What is hypertrophy? Examples when this occurs?
Increase in size of cells/organs (consequentially) caused by increased functional demand or hormone stimulation. Occurs in athletes’ muscles and heart, as well as breasts during menstruation in women, and uterus during pregnancy.
What is hyperplasia? Examples when this occurs?
An increase in the number of cells, can be both physiological or pathological. Occurs in the endometrium during oestrogen release, donating a kidney, and tutor in a hormonal gland.
What is dysplasia? Examples when this occurs?
An increase in the nuclear-cytoplasmic ratio (ie nucleus grows faster). Occurs in precancerous cells which show physiological and genetic features of malignancy but not invading underlying tissue.
What is metaplasia? Examples when this occurs?
When one adult type of cell becomes another adult cell type, reversibly. Examples: in Barrett’s oesophagus, acid reflux causes squamous epithelium to become columnar epithelium. In pregnancy, columnar epithelium in the cervix becomes squamous epithelium, caused by hormonal exposure of cells.
What are the types of reversible injury a cells can suffer? Which one is less reversible? Examples?
Cellular swelling or fatty change. Cellular swelling is less reversible. An example of fatty change is the fatty deposits in liver due to excessive alcohol intake.
What are the types of cell deaths? When do each of these occur?
Necrosis, apoptosis and necroptosis. Necrosis occurs I inflammation or cell injury, it is never a physiological response. Apoptosis is programmed cell death, and necropolis is programmed cell death through necrosis.
What can cause apoptosis?
Embryogenesis, mild injury casing irreparable damage to DNA, deletion of auto-reactive T cells in the thymus.
What are some distinct features of apoptosis compared to the other types of cell death?
It is the death of a single cell, there is no inflammation around it, is an active process and is programmed (ie physiological).
What are the types of necrosis? Examples when each of them occur?
Coagulative necrosis (cells become irreversible bound to each other, hence keep their shape once dead, eg. myocardial infarct), liquative necrosis (cells turn to liquid, eg. cerebral infarct and any general death in brain), caseous necrosis (cell structure is gone, seems granular,, eg. with TB) and fat necrosis (doused when enzymatic tissues die and leak, so enzymes act on cells, releasing free fatty acids (in pancreas) which react with Ca+ and precipitate, eg. with acute pancreatitis).
