Innervation of the equine intrinsic laryngeal muscles

Section: Introductionmentioning

confidence: 99%

Biomechanical characterisation of equine laryngeal cartilage

Passman¹,

Cheetham²,

Bonassar

et al. 2011

“…Recurrent laryngeal neuropathy (RLN) is a major cause of poor performance in racehorses and affects 1.6-8% of Thoroughbreds Lane et al 1987;Dixon et al 2001;Brown et al 2005). The caudal (recurrent) laryngeal nerve innervates the dorsal cricoarytenoid (DCA) muscle and produces abduction of the vocal process of the arytenoid cartilage (Quinlan et al 1982;Dyce et al 2002;König and Liebich 2004). RLN results in progressive atrophy of the DCA muscle and associated loss of arytenoid cartilage abduction (Cole 1946;Duncan et al 1974;Cahill and Goulden 1986).…”

Section: Introductionmentioning

confidence: 99%

Neuroanatomy of the equine dorsal cricoarytenoid muscle: Surgical implications

Cheetham

Radcliffe

Ducharme

et al. 2008

“…Epiglottitis was also found in racehorses that showed exercising intolerance, respiratory noise and coughing (Hawkins and Tulleners 1994). Of these diseases, laryngeal hemiplegia may be caused by dysfunction of laryngeal nerves (Rooney and Delaney 1970;Goulden and Anderson 1981;Quinlan et al 1982) and inhalation anaesthesia may cause bilateral arytenoid cartilage paralysis (Abrahamsen et al 1 9 9 0 ) . Therefore, the laryngeal nerves, which play an important role in respiratory modulation, are suggested to be associated with laryngeal diseases in racehorses.…”

Section: Introductionmentioning

confidence: 99%

Morphology of the nerve endings in laryngeal mucosa of the horse

Yamamoto

Atoji

Hobo

et al. 2001

Summary To discuss the significance of laryngeal sensation on various disorders of the horse, we studied the morphological and topographical characteristics of sensory structures in the laryngeal mucosa using immunohistochemistry and immunoelectron microscopy. Various sensory structures, i.e. glomerular endings, taste buds and intraepithelial free nerve endings, were found in the laryngeal mucosa by immunohistochemistry for protein gene product 9.5 (PGP 9.5) and neurofilament 200kD (NF200). Glomerular nerve endings were distributed mainly in the epiglottic mucosa; some endings were also found in the arytenoid region arising from thick nerve fibres running through the subepithelial connective tissue. Some terminals directly contacted the epithelial cells. Taste buds were distributed in the epithelium of the epiglottis and aryepiglottic fold. In the whole mount preparation, the taste buds were supplied by the terminal branching of the thick nerve fibres. In some cases, the taste buds were arranged around the opening of the duct of the epiglottic glands. The intraepithelial free nerve endings were found to be immunoreactive for substance P (SP) and calcitonin gene‐related peptide (CGRP). These nerve endings were surrounded by the polygonal stratified epithelial cells in the supraglottic region, and by the ciliated cells in the subglottic region. The density of the intraepithelial free nerve endings was highest in the corniculate process of the arytenoid region and lowest in the vocal cord mucosa. The densities of CGRP‐ and SP‐immunoreactive nerve endings in the arytenoid region were (mean ± s.d.) 30.6 ± 12.0 and 10.0 ± 4.9 per unit epithelial length (1 mm), respectively and in the vocal fold mucosa, 1.1 ± 0.9 and 0.8 ± 0.7, respectively. Approximately one half of the CGRP immunoreactive nerve endings were immunoreactive for SP, and most SP‐immunoreactive nerve endings were also immunoreactive for CGRP. Well‐developed subepithelial plexus with numerous intraepithelial fibres were observed in flat or round mucosal projections that existed on the corniculate process of the arytenoid region. In conclusion, the laryngeal mucosa of the horse seems to have morphology‐ and/or location‐dependent sensory mechanisms against various endo‐and exogenious stimuli.