Physiology

Physiology (/ˌfɪziˈɒlədʒi/; from Ancient Greek φύσις (physis), meaning "nature, origin", and -λογία (-logia), meaning "study of"[1]) is the scientific study of normal function in living systems.[2] A sub-discipline of biology, its focus is in how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system.[3] Given the size of the field it is divided into, among others, animal physiology (including that of human), plant physiology, cellular physiology, microbial physiology (see microbial metabolism), bacterial physiology, and viral physiology.[3] Nobel Prize in Physiology or Medicine is awarded to those who make significant achievements in this discipline since 1901 by the Royal Swedish Academy of Sciences. In medicine, a physiologic state is one occurring from normal body function, rather than pathologically.

History

Physiological studies date back to ancient civilizations of India,[4][5] Egypt alongside anatomical studies but did not utilize dissections and vivisection.[6] The study of human physiology as a medical field dates back to at least 420 BC to the time of Hippocrates, also known as the father of medicine.[7] The critical thinking of Aristotle and his emphasis on the relationship between structure and function marked the beginning of physiology in Ancient Greece, while Claudius Galenus (c. 126–199 AD), known as Galen, was the first to use experiments to probe the functions of the body. Galen was the founder of experimental physiology.[8]

Jean Fernel (1497 - 1558), a French physician, introduced the term "physiology".[9]

In the 19th century, physiological knowledge began to accumulate at a rapid rate, in particular with the 1838 appearance of the Cell theory of Matthias Schleiden and Theodor Schwann. It radically stated that organisms are made up of units called cells. Claude Bernard's (1813–1878) further discoveries ultimately led to his concept of milieu interieur (internal environment), which would later be taken up and championed as "homeostasis" by American physiologist Walter Cannon. By homeostasis, Cannon meant "the maintenance of steady states in the body and the physiological processes through which they are regulated."[10]

In the 20th century, biologists also became interested in how organisms other than human beings function, eventually spawning the fields of comparative physiology and ecophysiology.[11] Major figures in these fields include Knut Schmidt-Nielsen and George Bartholomew. Most recently, evolutionary physiology has become a distinct subdiscipline.[12]

Subdisciplines

There are many ways to categorize the subdiscplines of physiology:[13]

Human physiology

Human physiology seeks to understand the mechanisms that work to keep the human body alive and functioning,[3] through scientific enquiry into the nature of mechanical, physical, and biochemical functions of humans, their organs, and the cells of which they are composed. The principal level of focus of physiology is at the level of organs and systems within systems. The endocrine and nervous systems play major roles in the reception and transmission of signals that integrate function in animals. Homeostasis is a major aspect with regard to such interactions within plants as well as animals. The biological basis of the study of physiology, integration refers to the overlap of many functions of the systems of the human body, as well as its accompanied form. It is achieved through communication that occurs in a variety of ways, both electrical and chemical.

Much of the foundation of knowledge in human physiology was provided by animal experimentation. Physiology is the study of function and is closely related to anatomy which is the study of form. Due to the frequent connection between form and function, physiology and anatomy are intrinsically linked and are studied in tandem as part of a medical curriculum.

See also

References

  1. ↑ "physiology". Online Etymology Dictionary.
  2. ↑ Prosser, C. Ladd (1991). Comparative Animal Physiology, Environmental and Metabolic Animal Physiology (4th ed.). Hoboken, NJ: Wiley-Liss. pp. 1–12. ISBN 0-471-85767-X.
  3. ↑ 3.0 3.1 3.2 Hall, John (2011). Guyton and Hall textbook of medical physiology (12th ed. ed.). Philadelphia, Pa.: Saunders/Elsevier. p. 3. ISBN 978-1-4160-4574-8.
  4. ↑ D. P. Burma and Maharani Chakravorty. From Physiology and Chemistry to Biochemistry. Pearson Education. p. 8.
  5. ↑ Francis Zimmermann. The Jungle and the Aroma of Meats: An Ecological Theme in Hindu Medicine. Motilal Banarsidass publications. p. 159.
  6. ↑ http://books.google.com/books?id=LKdC0fDmnT4C&pg=PA43&dq=ancient+egyptian+medicine++physiology&hl=en&sa=X&ei=1UKaU6OZCZenyASB5IKoBA&ved=0CEsQ6AEwCA#v=onepage&q=ancient%20egyptian%20medicine%20%20physiology&f=false
  7. ↑ "Physiology". Science Clarified. Advameg, Inc. Retrieved 2010-08-29.
  8. ↑ Fell, C.; Pearson, F. (November 2007). "Historical Perspectives of Thoracic Anatomy". Thoracic Surgery Clinics 17 (4): 443–8. doi:10.1016/j.thorsurg.2006.12.001.
  9. ↑ Wilbur Applebaum. Encyclopedia of the Scientific Revolution: From Copernicus to Newton. Routledge. p. 344.
  10. ↑ Theodore M. Brown and Elizabeth Fee, “Walter Bradford Cannon: Pioneer Physiologist of Human Emotions” in American Journal of Public Health. 2002 October; 92(10): 1594–1595. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1447286/
  11. ↑ Feder, ME; Bennett, AF; WW, Burggren; Huey, RB (1987). New directions in ecological physiology. New York: Cambridge University Press. ISBN 978-0-521-34938-3.
  12. ↑ Garland, Jr, Theodore; Carter, P. A. (1994). "Evolutionary physiology" (PDF). Annual Review of Physiology 56 (56): 579–621. doi:10.1146/annurev.ph.56.030194.003051. PMID 8010752.
  13. ↑ Moyes, C.D., Schulte, P.M. Principles of Animal Physiology, second edition. Pearson/Benjamin Cummings. Boston, MA, 2008.

External links

Look up physiology in Wiktionary, the free dictionary.
Wikisource has original works on the topic: Physiology

Bibliography

Human physiology

Animal physiology

Plant physiology

Fungi physiology

Protist physiology

Algae physiology

Protozoa physiology

Bacterial physiology