title: Sexual dimorphism in the histologic organization of the muscle fibers in human tongue.
abstract: Tongue movements are critical for speech, swallowing, and respiration; and tongue dysfunction could lead to dysarthria, dysphagia, and obstructive sleep apnea, respectively. Our current understanding of the contributions of specific tongue muscles (TOs) to precise movement patterns is limited. Likewise, there is still little information regarding the orientation of histologic muscle fibers of the tongue in humans, especially between men and women. Thus, the aim of this study was to compare the histologic organization in the tongue of men and women. Ten tongues were studied in human specimens obtained from necropsies (five men and five women). The muscles were analyzed using histology, and the morphometric parameters were measured using Image Pro-Plus Software (Image Pro-Plus 6.0; Media Cybernetics, Silver Spring, MD). Slices were obtained from the anterior, median, and posterior parts of the tongue. We classified and estimated the percentages of transverse (T), oblique (O), and longitudinal (L) fibers in the tongue. To quantify the percentage of fibers in each category in the tongue, the shape coefficient (Shape Z) was estimated. Statistical differences were found between the orientation of the muscle fibers of men and women only for the middle region of the tongue. The middle region of the tongue in women compared with men has a smaller difference in the variation of the percentage of fibers T (P=0.0004), O (P=0.0006), and L (P=0.0013). These morphologic findings are probably related to physiological differences.
authors.affiliation: Departamento de Biologia e Farmácia, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brazil. Electronic address: dcampos@unisc.br.
authors.forename: Deivis
authors.initials: D
authors.lastname: de Campos
authors.affiliation: Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Departamento de Ciências Morfológicas, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Geraldo Pereira
authors.initials: GP
authors.lastname: Jotz
authors.affiliation: Departamento de Biologia e Farmácia, Universidade de Santa Cruz do Sul, Santa Cruz do Sul, Rio Grande do Sul, Brazil.
authors.forename: Layana
authors.initials: L
authors.lastname: Heck
authors.affiliation: Laboratório de Biologia Celular e Tecidual, Departamento de Ciências Morfofisiológicas, Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Léder Leal
authors.initials: LL
authors.lastname: Xavier
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D002452:Cell Count / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D018485:Muscle Fibers, Skeletal / Q000166:cytology*; D012727:Sex Characteristics; D014059:Tongue / Q000166:cytology*
keywords: Histology; Human; Sexual dimorphism; Stereology; Tongue muscle