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Autonomic‐somatic communications in the human pelvis: computer‐assisted anatomic dissection in male and female fetuses
Author(s) -
Alsaid Bayan,
Moszkowicz David,
Peschaud Frédérique,
Bessede Thomas,
Zaitouna Mazen,
Karam Ibrahim,
Droupy Stéphane,
Benoit Gérard
Publication year - 2011
Publication title -
journal of anatomy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.932
H-Index - 118
eISSN - 1469-7580
pISSN - 0021-8782
DOI - 10.1111/j.1469-7580.2011.01416.x
Subject(s) - clitoris , pudendal nerve , medicine , anatomy , pelvis , dissection (medical) , urethral sphincter , autonomic nervous system , sphincter , urethra , heart rate , blood pressure
Sphincter continence and sexual function require co‐ordinated activity of autonomic and somatic neural pathways, which communicate at several levels in the human pelvis. However, classical dissection approaches are only of limited value for the determination and examination of thin nerve fibres belonging to autonomic supralevator and somatic infralevator pathways. In this study, we aimed to identify the location and nature of communications between these two pathways by combining specific neuronal immunohistochemical staining and three‐dimensional reconstruction imaging. We studied 14 normal human fetal pelvic specimens (seven male and seven female, 15–31 weeks’ gestation) by three‐dimensional computer‐assisted anatomic dissection (CAAD) with neural, nitrergic and myelin sheath markers. We determined the precise location and distribution of both the supra‐ and infralevator neural pathways, for which we provide a three‐dimensional presentation. We found that the two pathways crossed each other distally in an X‐shaped area in two spatial planes. They yielded dual innervation to five targets: the anal sphincter, levator ani muscles, urethral sphincter, corpus spongiosum and perineal muscles, and corpora cavernosa. The two pathways communicated at three levels: proximal supralevator, intermediary intralevator and distal infralevator. The dorsal penis/clitoris nerve (DN) had segmental nitrergic activity. The proximal DN was nNOS‐negative, whereas the distal DN was nNOS‐positive. Distal communication was found to involve interaction of the autonomic nitrergic cavernous nerves with somatic nitrergic branches of the DN, with nitrergic activity carried in the distal part of the nerve. In conclusion, the pelvic structures responsible for sphincter continence and sexual function receive dual innervation from the autonomic supralevator and the somatic infralevator pathways. These two pathways displayed proximal, intermediate and distal communication. The distal communication between the CN and branches of the DN extended nitrergic activity to the distal part of the cavernous bodies in fetuses of both sexes. These structures are important for erectile function, and care should therefore be taken to conserve this communication during reconstructive surgery.