With the advances of immunohistochemistry in combination with confocal
microscopy, airway sensory receptor end-organs can now be examined and
evaluated objectively. Based on their 'neurochemical coding',
morphology, location and origin, three sensory receptor end organs are
currently morphologically well-characterised: smooth muscle-associated
airway receptors (SMARs), neuroepithelial bodies (NEBs) and visceral
pleura receptors (VPRs). The present information on the functional
morphological and neurochemical characteristics of these sensory
receptors, leads to important conclusions about their (possible)
function.