August 2012

Normal taste and smell function depend upon renewal of taste and smell receptors

Taste and smell function depend upon growth factor secretions from multiple organ systems which initiate and maintain taste buds and olfactory epithelial cells. These secretions arise from these multiple organ systems and are funneled through saliva to activate and maintain taste buds and through nasal mucus to activate and maintain olfactory epithelial cells. These secretions act on stem cells in taste buds and olfactory epithelial cells to initiate and maintain growth of the cellular components which make these sensory organs function. Without these secretions taste buds and olfactory epithelial cells exhibit apoptosis (cellular degeneration) and inflammation (necrosis) which inhibit taste bud and olfactory epithelial cell growth and development and cause taste and smell dysfunction.

What are the characteristics of these sensory organs by which these secretions act to maintain them? The cellular components of these sensory organs turn over very rapidly. All cells in most taste buds turn over completely every 24 hours. All cells in olfactory epithelium turn over within a period of 1-30 days. These sensory organs do not contain blood vessels, lymphatics or exhibit mitosis. It is only the stem cells in these organs which exhibit mitosis and thereby initiate this growth process. Because of their rapid turn over these cells require continual presence of growth factors to initiate and RENEW their cellular components.

Since it is only the stem cells of each of these sensory organs which respond to these growth factors secretion of these growth factors must be constant to maintain and RENEW the cellular components within taste buds and olfactory epithelial cells. If these secretions decrease the stem cells are not adequately stimulated and cause loss of taste buds and olfactory epithelial cells with subsequent loss of taste and smell.