Biological regeneration . Autonomous repair or restoration mechanism of living organisms, of organs or tissues aged, damaged or lost, by cells of the same lineage, for physiological or pathological causes.
Summary
[ hide ]
- 1 Demonstrations
- 2 Mechanisms
- 3 Regeneration capacity
- 4 Sources
Manifestations
In the field of botany , new methods were slowly incorporated to improve the characteristics and propagation of plants . The planting of selected cuttings or cuttings and the preparation of layers or margins for the regeneration and multiplication of new plants from them were introduced. The different grafting methods used mainly in floriculture and arboriculture were also developed.. With this, it was possible to perpetuate a plant with certain properties that are desired to be conserved in the offspring, which is achieved by implanting or fixing a small portion (graft) of the donor plant on another that serves as a recipient and has been called foot or pattern. An indispensable requirement for the success of this procedure is the existence in the graft of one or more buds .
Among the new methods to improve the characteristics and propagation of plants are in vitro plant regeneration techniques , which include organogenesis and somatic embryogenesis that give the possibility of forming so-called “artificial seeds”.
In zoology, regenerative capacity behaves differently in different types of animals, because while it is common in invertebrates , it is limited in most vertebrates . Lower animals are known to possess greater regenerative power than higher animals. Example: planarians , hydra , starfish and shellfish .
Many vertebrates have lost, at least in a significant way, the regenerative potential of most of their tissues and organs. However, some have retained remarkable regenerative ability, including teleost fish , urodels ( salamanders and newts ), and other types of amphibians. The turtles , crocodiles and snakes have generally lost the ability to regenerate lost parts. the lizards, have the possibility of regenerating the tail. Mammals also have limitations, since they cannot regenerate limbs, organs and tissues in the same way that some lower animals do. However, there are exceptions, including deer , dolphin, and some types of mice such as those in the MRL line.
In the particular case of human beings, although they also possess a certain degree of regenerative ability, this is much more limited, expressing only some regenerative physiological processes or before some lesions, which are mainly manifested in the epidermal cells of the oral mucosa and the tract. respiratory , blood cells , hair , nails , muscle tissue , skin, and bone tissue . New knowledge about stem cells has opened a new era that offers man possibility of influencing the regeneration of organs and tissues therapeutically.
Mechanisms
There are three mechanisms by which regeneration, epimorphosis, morphalaxis, and compensatory regeneration can be facilitated.
- Epimorphic regeneration is characterized by the differentiation of a blastemaand the de novo generation of tissues or body parts, this type of regeneration is typical of limb regeneration. When they refer to the regeneration of the fin of teleost fish or the limb of urodels, they are talking about epimorphosis
- Regeneration by morphalaxis involves the transformation of parts of the body or existing tissues into new structures, this reorganization of the pattern is accompanied by limited new growth. When they refer to the regeneration of the hydra, one is in the presence of a process of morphalaxis.
The key to differentiating both processes is the existence of the blastema, a concept directly related to active cell proliferation.
- Compensatory regeneration can be seen as an intermediate way in which cells divide but maintain their differentiated functions by producing similar cells and therefore do not form undifferentiated cell masses. A single part of the body can regenerate the entire organ. In the Asteroids (starfish) of an arm the whole organism can regenerate, the body that is formed is proportional to the arm.
Regeneration capacity
It depends on:
1.Differentiation of your cells: The greater the cell differentiation, the less is the capacity of their regeneration.
The regeneration capacity can be:
- Permanent, such as in Neurons, Gonocytes and Muscles .
- Stable, as in the Liver(Border Line: it has a great capacity for regeneration despite the fact that its cells are very differentiated), Kidney and Endocrine organs.
- Labile, in the case of the Connective Tissue, Blood and Epithelium .
- Average cell life: If the cell average life is short, then they have great capacity for multiplication or regeneration. An example of this is Hematopoietic Cells.
- Cell DivisionCapacity : This depends on the previous sections. When the cell half-life is short, there is a great capacity for multiplication and a “pool” of undifferentiated cells is produced.
