title: Mechanoreceptors and nerve endings of the triangular fibrocartilage in the human wrist.
abstract: OBJECTIVE
  To increase our understanding of the mechanism of pain and the sensation of wrist instability by studying the distribution of the mechanoreceptors in the triangular fibrocartilage (TFC).
  
  
  METHODS
  The distribution and density of the nerve endings were investigated in 34 TFC specimens obtained from human cadavers. We studied the dorsal, palmar, ulnar, radial, and central areas after staining by a modified gold chloride technique.
  
  
  RESULTS
  The free nerve endings, responsible for sensing pain, predominate in the ulnar and dorsal areas. The Vater-Pacini corpuscles predominate in the radial and dorsal area, promoting perception of the onset or cessation of movement and mechanical stress change. The Golgi-Mazzoni corpuscles were more frequent in the ulnar and ventral areas, linking these areas to function of slow adaptation and sensation of extreme movements. The proprioceptive function receptors were found in all areas of TFC because Ruffini corpuscles have homogeneous distribution in this fibrocartilaginous tissue.
  
  
  CONCLUSIONS
  Our results showed that the nerve endings were distributed at the periphery of TFC and showed different concentrations of each type of mechanoreceptors per topographic area, suggesting that they play specific roles in the proprioceptive and nociceptive reflexes of the wrist.
authors.affiliation: Department of Orthopedics, University of São Paulo, Faculty of Medicine, Sao Paulo, Brazil.
authors.forename: Maria Luzete C
authors.initials: ML
authors.lastname: Cavalcante
authors.forename: Consuelo Junqueira
authors.initials: CJ
authors.lastname: Rodrigues
authors.forename: Rames
authors.initials: R
authors.lastname: Mattar
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002102:Cadaver; D002358:Cartilage, Articular / Q000166:cytology / Q000294:innervation*; D006801:Humans; D008465:Mechanoreceptors / Q000648:ultrastructure*; D008875:Middle Aged; D009411:Nerve Endings / Q000648:ultrastructure*; D013194:Staining and Labeling; D014953:Wrist / Q000033:anatomy & histology* / Q000294:innervation*