9. Why do cells die? What are the forms of cell death and what are the differences?

When cells are seriously damaged and involve the nucleus, they show irreversible changes such as metabolic stagnation, structural damage and functional loss, which is called cell death. Nucleated cells will die.

Cell death includes necrosis and apoptosis.

There are many reasons for death. As long as all damage factors act on a certain intensity or last for a certain time, so that the metabolism of damaged tissues stops completely, cells and tissues will die.

In most cases, necrosis is gradually developed by the degeneration of tissues and cells, which is called progressive necrosis.

During this period, as long as there is no necrosis and the cause is eliminated, the damage of tissues and cells can still be recovered (recoverable).

However, once the tissues and cells are seriously damaged, the metabolism is disordered and a series of morphological changes occur, the damage cannot be recovered (irreversible).

In some cases, due to the strong pathogenic factors, necrosis can occur rapidly, sometimes even without obvious morphological changes.