RT Journal Article
T1 Female Longitudinal Anal Muscles or Conjoint Longitudinal Coats Extend into the Subcutaneous Tissue along the Vaginal Vestibule: A Histological Study Using Human Fetuses
A1 Kinugasa, Yusuke
A1 Arakawa, Takashi
A1 Abe, Hiroshi
A1 Rodríguez Vázquez, José Francisco
A1 Murakami, Gen
A1 Sugihara, Kenichi
AB PurposeIt is still unclear whether the longitudinal anal muscles or conjoint longitudinal coats (CLCs) are attached to the vagina, although such an attachment, if present, would appear to make an important contribution to the integrated supportive system of the female pelvic floor.Materials and MethodsUsing immunohistochemistry for smooth muscle actin, we examined semiserial frontal sections of 1) eleven female late-stage fetuses at 28-37 weeks of gestation, 2) two female middle-stage fetus (2 specimens at 13 weeks), and, 3) six male fetuses at 12 and 37 weeks as a comparison of the morphology.ResultsIn late-stage female fetuses, the CLCs consistently (11/11) extended into the subcutaneous tissue along the vaginal vestibule on the anterior side of the external anal sphincter. Lateral to the CLCs, the external anal sphincter also extended anteriorly toward the vaginal side walls. The anterior part of the CLCs originated from the perimysium of the levator ani muscle without any contribution of the rectal longitudinal muscle layer. However, in 2 female middle-stage fetuses, smooth muscles along the vestibulum extended superiorly toward the levetor ani sling. In male fetuses, the CLCs were separated from another subcutaneous smooth muscle along the scrotal raphe (posterior parts of the dartos layer) by fatty tissue.ConclusionIn terms of topographical anatomy, the female anterior CLCs are likely to correspond to the lateral extension of the perineal body (a bulky subcutaneous smooth muscle mass present in adult women), supporting the vaginal vestibule by transmission of force from the levator ani.
PB Yonsei University College of Medicine
SN 0513-5796
SN 1976-2437
YR 2013
FD 2013-03-19
LK https://hdl.handle.net/20.500.14352/110639
UL https://hdl.handle.net/20.500.14352/110639
LA eng
NO Kinugasa Y, Arakawa T, Abe H, Rodríguez-Vízquez JF, Murakami G, Sugihara K. Female Longitudinal Anal Muscles or Conjoint Longitudinal Coats Extend into the Subcutaneous Tissue along the Vaginal Vestibule: A Histological Study Using Human Fetuses. Yonsei Med J. 2013 May;54(3):778-784. https://doi.org/10.3349/ymj.2013.54.3.778
DS Docta Complutense
RD 27 abr 2025