Origin of regeneration
Related formsnon·re·gen·e·ra·tion, noun
Examples from the Web for regeneration
“I need clothes, and a big long scarf,” he says as he comes round from the regeneration.Doctor Who’s ‘Deep Breath’: The 2,000-Year-Old Time Lord Grows Up|Nico Hines|August 8, 2014|DAILY BEAST
The regeneration of al Qaeda in Iraq and its expansion into Syria is a warning to American decision makers.Zarqawism Lives: Iraq’s al Qaeda Nightmare Is Back|Bruce Riedel|August 12, 2013|DAILY BEAST
Eye in the Door, The Ghost Road, and Regeneration, all by Pat Barker.
Scorpio rules death, sleep and sex, all falling under the heading of regeneration.
If one cut off the head, a new head will be formed in a few days, this being a case of regeneration.The Biological Problem of To-day|Oscar Hertwig
The problem of regeneration wasn't as easy as it usually is.Accidental Flight|Floyd L. Wallace
This last terrible experience has been the keystone of my regeneration.Yolanda: Maid of Burgundy|Charles Major
“Better live to see the regeneration of our faith, and our restoration to our rights,” rejoined Catesby.Guy Fawkes|William Harrison Ainsworth
The final stages of this regeneration of nature will not be reached until the Millennium has run its blessed course.The Articles of Faith|James E. Talmage
British Dictionary definitions for regeneration
Medicine definitions for regeneration
Science definitions for regeneration
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.