M M Bertrand1,2, B Alsaid3, S Droupy4, J Ripoche5,6, G Benoit7, P Adalian8, C Brunet9, M D Piercecchi-Marti10, M Prudhomme5,6. 1. Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nîmes, University Montpellier, 30 rue Lunaret, 34090, Montpellier, France. martinmbertrand@yahoo.fr. 2. Visceral and Digestive Surgery Department, CHU de Nimes, University Montpellier 1, Nimes, France. martinmbertrand@yahoo.fr. 3. Laboratory of Anatomy Faculty of Medicine, University of Damascus, Damascus, Syria. 4. Urology-Andrology Department, CHU de Nimes, University Montpellier 1, Nimes, France. 5. Laboratory of Experimental Anatomy Faculty of Medicine Montpellier-Nîmes, University Montpellier, 30 rue Lunaret, 34090, Montpellier, France. 6. Visceral and Digestive Surgery Department, CHU de Nimes, University Montpellier 1, Nimes, France. 7. Laboratory of Experimental Surgery, EA 4122, Faculty of Medicine, Bicêtre-Paris 11 University, Le Kremlin-Bicêtre, France. 8. Aix-Marseille Université, CNRS, EFS, ADES UMR 7268, 13916, Marseille, France. 9. Department of Digestive Surgery, Hôpital Nord, Aix-Marseille Université, Chemin des Bourrely, 13915, Marseille Cedex 20, France. 10. Service de médecine légale droit de la Santé-Aix-Marseille université UMR 7268 ADES, 13344, Marseille Cedex 15, France.
Abstract
PURPOSE: (1) Describe both nervous pathways to the sphincters, and highlight the anatomical support of their coordination. (2) Obtain a 3D representation of this complex innervation system. METHODS: A computer-assisted anatomical dissection technique was used. Serial histological sections were cut in the pelvis of four female human foetuses (aged 19-32 weeks of gestation). The sections were treated with conventional staining, and with seven different immunostainings. The sections were digitalized and, finally, a 3D representation was built from the corresponding images. RESULTS: Myelinated and sensory fibres were detected at the inferior hypogastric plexus (IHP) level. Our analysis showed that most of the afferent sensory fibres come from the urinary and anal sphincters through the anterior and posterior branches of the IHP respectively. A highly positive nitrergic (anti-NOS1) and sensitive (anti-CGRP) labelling was found in the external layer of the urethral sphincter. The 3D representation allowed describing the two components of the innervation system. A sensory-motor regulation loop was found for both sphincters. CONCLUSION: A 3D description of the components of both nervous pathways to the sphincters has been established. Our findings on the innervation of the sphincters tend to question the classical infra/supra levatorian muscle description. The coordinated work of the internal and external layers of the anal and urethral sphincter is probably mediated by multiple roles regulation.
PURPOSE: (1) Describe both nervous pathways to the sphincters, and highlight the anatomical support of their coordination. (2) Obtain a 3D representation of this complex innervation system. METHODS: A computer-assisted anatomical dissection technique was used. Serial histological sections were cut in the pelvis of four female human foetuses (aged 19-32 weeks of gestation). The sections were treated with conventional staining, and with seven different immunostainings. The sections were digitalized and, finally, a 3D representation was built from the corresponding images. RESULTS: Myelinated and sensory fibres were detected at the inferior hypogastric plexus (IHP) level. Our analysis showed that most of the afferent sensory fibres come from the urinary and anal sphincters through the anterior and posterior branches of the IHP respectively. A highly positive nitrergic (anti-NOS1) and sensitive (anti-CGRP) labelling was found in the external layer of the urethral sphincter. The 3D representation allowed describing the two components of the innervation system. A sensory-motor regulation loop was found for both sphincters. CONCLUSION: A 3D description of the components of both nervous pathways to the sphincters has been established. Our findings on the innervation of the sphincters tend to question the classical infra/supra levatorian muscle description. The coordinated work of the internal and external layers of the anal and urethral sphincter is probably mediated by multiple roles regulation.