title: Morphologic evaluation of the fetal recurrent laryngeal nerve and motor units in the thyroarytenoid muscle.
abstract: This study is a morphologic description of the recurrent laryngeal nerve (RLN) and of the number and size of motor units (MUs) in the thyroarytenoid (TA) muscle bilaterally of a human fetus aged 25 weeks. A quantitative analysis of RLN and MUs is presented to investigate similarities with equivalent structures in adults. In the fetus used in our study, the morphologic organization of the RLN was similar to that commonly described in the adult RLN. Moreover, as is observed in adult TA, the TA of the analyzed fetus, particularly the right TA, showed MUs typical of muscles with great motor accuracy. These results may be used to increase our knowledge of the features of the voice in adults and newborns.
authors.affiliation: Laboratório de Histologia e Patologia, Departamento de Biologia e Farmácia, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brazil; Curso de Ciências Biológicas, Departamento de Biologia e Farmácia, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brazil; Programa de Pós-Graduação em Biologia Celular e Molecular, Universidade Federal do Rio Grande do Sul, Campus do Vale, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Joel Henrique
authors.initials: JH
authors.lastname: Ellwanger
authors.forename: João Paulo
authors.initials: JP
authors.lastname: da Costa Rosa
authors.forename: Iuri Pereira
authors.initials: IP
authors.lastname: dos Santos
authors.forename: Helen Tais
authors.initials: HT
authors.lastname: da Rosa
authors.forename: Geraldo Pereira
authors.initials: GP
authors.lastname: Jotz
authors.forename: Léder Leal
authors.initials: LL
authors.lastname: Xavier
authors.forename: Deivis
authors.initials: D
authors.lastname: de Campos
mesh_terms: D005260:Female; D005333:Fetus / Q000166:cytology / Q000294:innervation; D006801:Humans; D007821:Laryngeal Muscles / Q000166:cytology / Q000196:embryology / Q000294:innervation*; D009046:Motor Neurons / Q000166:cytology*; D012009:Recurrent Laryngeal Nerve / Q000166:cytology / Q000196:embryology*
keywords: Fetus; Microanatomy; Motor units; Recurrent laryngeal nerve; Thyroarytenoid muscle