2015 Vision

Protective mechanisms

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There are two fundamental protective mechanisms for the eye. Regulation of eyelid position (including BLINKING) involves striated (ACh; nicotinic) and smooth (NE; α1 adrenergic) muscles.  TEAR PRODUCTION occurs spontaneously (basal), reflexly or in response to emotional stimuli, and is partially regulated by the parasympathetic nervous system (ACh; muscarinic).  EPIPHORA (overflow of tears) can be due to either overproduction or blocked drainage.


Email: Dr. Janet Fitzakerley | ©2015 University of Minnesota Medical School Duluth | Last modified: 12-feb-15 6:05 AM