regenerate

regenerate

Regeneration is that the whole or organ of an organism is injured by external force and part of it is lost. On the basis of the remaining part, it grows the same structure as the lost part in shape and function. This repair process is called regeneration.

definition

Regeneration: after tissue injury, it is repaired by the same kind of cells around the injury, which is called regeneration.

type

1. Complete regeneration: refers to the complete recovery of the original structure and function of the regenerated cells. 2. Incomplete regeneration: regeneration through fibrous tissue, also known as scar repair.

Regeneration ability

1. Labile cells: such as epidermal cells, respiratory and digestive tract epithelial cells. Stable cells: including the parenchymal cells of various glands or adenoid organs. 3. Permanent cells: including nerve cells, skeletal muscle cells and myocardial cells.

Regeneration of various tissues

1. Regeneration of epithelial tissue: (1) regeneration of covered epithelium: when the squamous epithelium is defective, the cells in the basal layer at the edge or bottom of the wound divide and proliferate, migrate to the center of the defect, form a single layer of epithelium first, and then proliferate and differentiate into squamous epithelium. (2) regeneration of glandular epithelium: the regeneration of glandular epithelium varies with the injured state. When the glandular structure (including basement membrane) is completely destroyed, it is difficult to regenerate. 2. Regeneration of fibrous tissue: fibroblasts in the damaged area divide and proliferate under stimulation. 3. Regeneration of cartilage and bone tissue: cartilage starts from the proliferation of perichondrium, and bone tissue has strong regeneration ability and can be completely repaired. (1) regeneration of capillary: budding way. (2) repair of large blood vessels: surgical anastomosis is needed for the disconnection of large blood vessels, and the endothelial cells on both sides of the anastomosis divide and proliferate, connect with each other, and restore the original intimal structure. It is difficult to regenerate the severed muscle layer completely. 5. Regeneration of muscle tissue: the regeneration ability of muscle tissue is very weak. The structure of striated muscle can be restored when the muscle membrane exists and the muscle fiber is not completely broken; the smooth muscle has a certain ability of division and regeneration, mainly through fiber scar connection; the ability of myocardial regeneration is very weak, generally scar repair. 6. Regeneration of nerve tissue: nerve cells in the brain and spinal cord cannot regenerate after being destroyed. When the peripheral nerve is damaged, if the nerve cells connected with it are still alive, it can be completely regenerated; if it is too far away from the two ends and there are scars between the two ends, it will form traumatic neuroma.

influence factor

Cell death and cell damage caused by various factors can stimulate cell proliferation. As the key link of regeneration, cell proliferation is largely regulated by extracellular microenvironment and various chemical factors. Excessive stimulator or inhibitor deficiency can lead to cell proliferation and uncontrolled growth of tumor. Cell growth can be achieved by shortening the cell cycle, but the most important factor is to re-enter the cell cycle.

The role of extracellular matrix in cell regeneration

extracellular matrix (ECM), ECM occupies a considerable proportion in any tissue. Its main function is to connect cells together, so as to support and maintain the physiological structure and function of the tissue, thus affecting the regeneration of cells. Studies have proved that although unstable cells and stable cells have complete regeneration ability, whether they can be reconstructed into normal structure still depends on ECM, because the latter regulates the biological function of cells They play a more active and complex role in behavior. It can affect cell morphology, differentiation, migration, proliferation and biological function. The information provided by it can regulate embryonic development, tissue reconstruction and repair, wound healing, fibrosis and tumor invasion. Therefore, extracellular matrix plays an important role in cell regeneration.

Chinese PinYin : Zai Sheng