regeneration

[ri-jen-uh-rey-shuhn]

noun

1. act of regenerating; state of being regenerated.

2. Electronics.,  a feedback process in which energy from the output of an amplifier is fed back to the grid circuit to reinforce the input.

3. Biology.,  the restoration or new growth by an organism of organs, tissues, etc., that have been lost, removed, or injured.

4. Theology.,  spiritual rebirth; religious revival.

regeneration

1. The regrowth of lost or destroyed parts or organs.

Other Word Forms

• nonregeneration noun

Word History and Origins

Origin of regeneration¹

1300–50; Middle English regeneracion < Late Latin regenerātiōn- (stem of regenerātiō ). See regenerate, -ion

A Closer Look

Regeneration of parts or, in some cases, nearly the entire body of an organism from a part, is more common than one might think. Many protists like the amoeba that have been cut in half can grow back into a complete organism so long as enough of the nuclear material is undamaged. Severed cell parts, such as flagella, can also be regrown in protists. New plants can be grown from cuttings, and plants can often be regenerated from a mass of fully differentiated cells (such as a section of a carrot root), which, if isolated in a suitable environment, turn into a mass of undifferentiated cells that develop into a fully differentiated organism. The capacity for regeneration varies widely in animals, with some able to regenerate whole limbs and others not, but the capacity is reduced significantly in more complex animals. Certain simple invertebrates like the hydra are always regenerating themselves. If cut into tiny pieces that are then mixed up, the pieces can reorganize themselves and grow back into a complete organism. Flatworms have the capacity to regenerate themselves from only a small mass of cells. If they are chopped up into fine pieces, each piece has the capacity to develop into an entire organism. Starfish, which are echinoderms, can regenerate their entire body from their central section and a single arm. Newts and salamanders can regenerate lost legs and parts of eyes, but many other amphibians such as frogs and toads cannot. Certain lizards can regenerate their tails. In many animals, these regenerated body parts are not as large as the originals but are usually sufficient to be functional. Many higher animals such as mammals regularly regenerate certain tissues such as hair and skin and portions of others such as bone, but most tissues cannot be regenerated. About 75 percent of the human liver can be removed, and it will regenerate into a functional organ. The physiological reasons for this are still not understood. Regeneration in this case takes the form of the enlargement of the remaining structures rather than the re-creation of the lost ones. Thus, there are four mechanisms for tissue regeneration in animals: the reorganization of existing cells (as in the hydra), the differentiation of stored stem cells into the specific tissues needed (as in the salamander), the dedifferentiation of neighboring tissue cells and their subsequent regrowth as cells of the needed type (as in plants as well as certain animals like the salamander), and the compensatory growth of the surviving cells of the specific tissue (as in the human liver). There is a great interest in stem cells because of their potential use in regenerating body tissues, such as nerve cells and heart muscle. The biochemical mechanisms for dedifferentiation are also the subject of intense study.

Example Sentences

Stem cells already play a central role in cutting-edge work on tissue repair and regeneration.

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"Rhyl's regeneration is under way," said the council, "but this long-term vision takes time".

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Scientists have long known that macrophages respond to muscle injury by releasing cytokines and chemokines that create inflammation, influence pain, and help drive the growth and regeneration of muscle fibers.

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This is a project that has been developed over a number of years and is part of a wider city regeneration scheme linked to the local council, the Executive and the Belfast region city deal.

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When wounds occurred, the ISR activated even more strongly, prioritizing healing over hair regeneration.

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Related Words

• rebirth 
• reclamation 
• reconstruction 
• transformation 

When To Use

What does regeneration mean?

Regeneration is the process of regenerating—renewing or restoring something, especially after it has been damaged or lost. A close synonym is regrowth.Regenerate and regeneration are commonly used in the context of biology to refer to the regrowth of part of an organism or environment. In animals, tissue, organs, or other body parts that have been injured or lost are sometimes regenerated. In some animals, regeneration happens on an even greater scale, with some being able to regrow an entire limb or tail. Environments that have been damaged or destroyed, like forests or grasslands damaged by fire, can also undergo regeneration.Regeneration can also be used in other specific ways.In the context of religion, regeneration is used to refer to a kind of spiritual rebirth. In city planning and development, regeneration is sometimes used as a synonym for redevelopment. In the context of data storage, regeneration is a method used to improve the speed and reliability of networks. In audio electronics, regeneration refers to a kind of feedback process that increases amplification.Example: It is hoped that the experimental treatment will reduce healing time due to faster tissue regeneration.