Compensatory growth (organ)

Compensatory growth is a type of regenerative growth that can take place a number of human organs after the organs are either damaged, removed, or cease to function.^[1] Additionally, increased functional demand can also stimulate this growth in tissues and organs.^[2] The growth can be a result of increased cell size (compensatory hypertrophy) or an increase in cell division (compensatory hyperplasia) or both.^[3] For instance, if one kidney is surgically removed, the cells of other kidney divide at an increased rate.^[1] Eventually, the remaining kidney can grow until its mass approaches the combined mass of two kidneys.^[1] Along with the kidneys, compensatory growth has also been characterized in a number of other tissues and organs including:

• the adrenal glands^[4][5]
• the heart^[5][6]
• muscles^[5]
• the liver^[5][7]
• the lungs^[8]
• the pancreas (beta cells and acinar cells)^[7]
• the mammary gland^[5]
• the spleen (where bone marrow and lymphatic tissue undergo compensatory hypertrophy and assumes the spleen function during spleen injury)^[5]
• the testicles^[5]
• the thyroid gland^{[5] [9]}

A large number of growth factors and hormones are involved with compensatory growth, but the exact mechanism is not fully understood and probably varies between different organs.^[1] Nevertheless, angiogenic growth factors which control the growth of blood vessels are particularly important because blood flow significantly determines the maximum growth of an organ.^[1]

Compensatory growth may also refer to the accelerated growth following a period of slowed growth, particularly as a result of nutrient deprivation.

See also

• Hyperplasia
• Hypertrophy
• Cellular adaptation

References

1. ^ ^{a b c d e} Widmaier E. P., Raff H., and Strang K. T. (2006). Vander's Human Physiology: The Mechanisms Of Body Function (10 ed.). Boston, Mass: McGraw-Hill Companies. pp. 383. ISBN 978-0072827415. 
2. ^ Goss, R. (1965). "Kinetics of Compensatory Growth". The Quarterly review of biology 40: 123–146. PMID 14338253.  edit
3. ^ "compensatory growth (biology) -- Britannica Online Encyclopedia". http://www.britannica.com/EBchecked/topic/129769/compensatory-growth. Retrieved 10 June 2011. 
4. ^ Swale Vincent (1912). Internal secretion and the ductless glands. Arnold. p. 150. http://books.google.com/books?id=7DVAAAAAIAAJ&pg=PA150. Retrieved 10 June 2011. 
5. ^ ^{a b c d e f g h} Francis Delafield; Theophil Mitchell Prudden (1907). A text-book of pathology with an introductory section on post-mortem examinations and the methods of preserving and examining diseased tissues. William Wood and Company. pp. 61–62. http://books.google.com/books?id=rh8SAAAAYAAJ&pg=PA62. Retrieved 10 June 2011. 
6. ^ M. I. Gabriel Khan (5 December 2005). Encyclopedia of heart diseases. Academic Press. pp. 493–494. ISBN 9780124060616. http://books.google.com/books?id=xco9aJ_Y9XIC&pg=PA493. Retrieved 10 June 2011. 
7. ^ ^{a b} Anthony Atala (2008). Principles of regenerative medicine. Academic Press. pp. 101–102. ISBN 9780123694102. http://books.google.com/books?id=BG5paiwd5hgC&pg=PA101. Retrieved 10 June 2011. 
8. ^ Rannels, D. (1989). "Role of physical forces in compensatory growth of the lung". The American journal of physiology 257 (4 Pt 1): L179–L189. PMID 2679138.  edit
9. ^ Harold Clarence Ernst (1919). The Journal of medical research. p. 199. http://books.google.com/books?id=xfKfAAAAMAAJ&pg=PA199. Retrieved 10 June 2011.