RT Journal Article
T1 Reappraisal of intergender differences in the urethral striated sphincter explains why a completely circular arrangement is difficult in females: a histological study using human fetuses
A1 Masumoto, Hiroshi
A1 Takenaka, Atsushi
A1 Rodríguez Vázquez, José Francisco
A1 Murakami, Gen
A1 Matsubara, Akio
AB To investigate why the development of a completely circular striated sphincter is so rare, we examined histological sections of 11 female and 11 male mid-term human fetuses. In male fetuses, the striated muscle initially extended in the frontal, rather than in the horizontal plane. However, a knee-like portion was absent in the female fetal urethra because, on the inferior side of the vaginal end, a wide groove for the future vestibule opened inferiorly. Accordingly, it was difficult for the developing striated muscle to surround the groove, even though there was not a great difference in width or thickness between the female vestibule and the male urethra. The development of a completely circular striated sphincter seems to be impossible in females because of interruption of the frontal plane by the groove-like vestibule. However, we cannot rule out the possibility that before descent of the vagina, the urethral striated muscle extends posteriorly.
PB Korean Association of Anatomists
SN 2093-3665
YR 2012
FD 2012
LK https://hdl.handle.net/20.500.14352/110947
UL https://hdl.handle.net/20.500.14352/110947
LA eng
NO Masumoto, Hiroshi, et al. «Reappraisal of Intergender Differences in the Urethral Striated Sphincter Explains Why a Completely Circular Arrangement Is Difficult in Females: A Histological Study Using Human Fetuses». Anatomy & Cell Biology, vol. 45, n.o 2, 2012, p. 79. DOI.org (Crossref), https://doi.org/10.5115/acb.2012.45.2.79.
DS Docta Complutense
RD 14 dic 2025