Re: Approximately how many nerves (all types) are in the average human's lips?

Dear Wayne,
   Since some skin areas are demonstrably more sensitive to tactile 
stimuli than others, (eg., the skin of the back is less sensitive to touch 
than the skin of the fingers) it has long been assumed that some skin 
areas have fewer sensory fibers.  However, this has not actually been 
measured in many studies.  One noteworthy study has explored this:  a 
paper by RS Johansson in Journal of Physiology, vol. 286:283, 
1979 "Tactile sensibility in the human hand: relative and absolute 
densities of four types of mechanoreceptive units in glabrous skin" 
established that the fingertips seem to have 240 fibers per square cm, 
whereas the less sensitive palm has only 58 fibers per square cm.  
Johansson recently also studied sensory fibers in the lips (see Behavioral 
Brain Research vol. 135:pp27-33, 2002) but did not quantify numbers of 
fibers there.  Due to their high sensitivity to touch, it is reasonable to 
assume the lips have more sensory fibers than other areas.  Lip sensations 
also occupy a much greater area of the sensory cortex of the brain than 
sensations from other skin areas (see AJ Guyton, Textbook of Medical 
Physiology, P. 570, 1971.)  You can access summaries of these papers by 
going to a web site called pubMed (www.pubmed.gov) and typing in the 
authors names