MUSCLES OF THE PELVIC OUTLET IN THE RHESUS-MONKEY (MACACA-MULATTA) WITH SPECIAL REFERENCE TO NERVE SUPPLY

Background: The manner of innervation of the muscles of the inferior l imb, pelvic outlet, and tail in rhesus monkey (Macaca mulatta) was inv estigated in detail in 11 pelvic halves of four males and two females. Results: The origins of the pudendal nerve were widespread and overla pped the sacral plexus. After removal of the bone structures, detailed dissection revealed the origin of the pudendal nerve to ventrocaudall y overlap the sacral plexus. This dorsoventral branching pattern betwe en the sacral plexus and the pudendal nerve is similar to that in Urod ela (Akita, 1992b), Lacertilia (Akita, 1992a) and Aves (Akita et al., 1992a), and is a basis for morphological understanding of the muscles of the pelvic outlet. Conclusions: The muscles of the pelvic outlet co nsist of the levator, sphincter, and tail muscle groups, based on the stratification of the supplying nerves the former two groups likely de rive from the ventral muscles of the inferior limb, and the latter gro up from the ventral caudal (trunk) muscles. (C) 1995 Wiley-Liss, Inc.