Definition of Aqueous humor

Aqueous humor: In medicine, humor refers to a fluid (or semifluid) substance. Thus, the aqueous humor is the fluid normally present in the front and rear chambers of the eye. It is a clear, watery fluid that flows between and nourishes the lens and the cornea; it is secreted by the ciliary processes.

The humors were part of an ancient theory that health came from balance between the bodily liquids. These liquids were termed humors. Disease arose when imbalance occurred between the humors. The humors were:

  • Phlegm (water)
  • Blood
  • Gall (black bile thought to be secreted by the kidneys and spleen)
  • Choler (yellow bile secreted by the liver)

This theory (which was variously called the humoral theory, humoralism, and humorism) was devised well before Hippocrates (c.460-c.375 BC). It was not definitively demolished until Rudolf Virchow published his formative book, Cellularpathologie, in 1858 that laid out the cellular basis of pathology. Present day pathology rests on a cellular and molecular foundation. The humors have been dispelled, except for the aqueous humor.


Last Editorial Review: 6/14/2012

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