There is no consensus about the role of the gubernaculum testis (GT). Nineteen human embryos (Carnegie stages 15-23), 36 fetuses (9 weeks to term), and eight neonates were examined. All the embryos and 25 fetuses (from weeks 9-16) were processed for paraffin wax histology and serially sectioned at 10 µm thickness. The remaining 11 fetuses and the eight neonates were fresh specimens that were dissected under a surgical microscope. The GT appeared during the embryonic period (stages 17-23) with a horseshoe-shaped mesenchyme condensation of the superior concavity, which was observed in four different topographical regions sequentially through development. The GT was not attached at either of its ends in any of the specimens, not to the gonad or in the scrotal sac. The inguinal canal differentiates around the inguinal portion of the GT during the late embryonic period. After stage 21, the GT appears enveloped by an evagination of the peritoneal cavity. It has few striate muscular fibers and vessels. Although the GT does not appear to have the role traditionally attributed to it, it is still an essential structure and indirectly facilitates the descent of the testes. It contributes to the formation of the inguinal canal and then forges the pathway that the testes will subsequently take through the inguinal canal as they migrate from the abdominal cavity into the scrotal sac. Clin. Anat. 30:599-607, 2017. © 2017 Wiley Periodicals, Inc.

Purpose Lumbar discogenic diffuse pain is still not understood. Authors describe the sinuvertebral nerve (SVN) as one possible cause. Body-donor studies are rare and controversial. Therefore, the aim was to revisit the origin, course and distribution in a body-donor study. Methods Six lumbar blocks (3 female, 3 male) aged between 59 and 94 years were dissected. After removal of the back muscles, lamina, dura mater and cauda equina, the anterior vertebral venous plexus, spinal artery and SVN were exposed and evaluated. Results 43 nerves out of 48 levels could be evaluated. The origin of the SVN was constituted by two roots: a somatic and a sympathetic branch arising from the rami communicantes. In 4/48 intervertebral canals studied (8.3%), we found two SVN at the same level. In 35/48 cases, one SVN was found. In 9/48 cases, no SVN was found. The SVN had a recurrent course below the inferior vertebral notch; in the vertebral canal it showed different patterns: ascending branch (31/43, 72.1%), common branch diverging into two branches (10/43, 23.3%), double ascending branch (1/43, 2.3%) finalizing two levels above and a descending branch (1/43, 2.3%). In 12/43 cases (27.9%) the SVN had ipsilateral connections with another SVN. The distribution ended in the middle of the vertebral body supplying adjacent structures. Conclusion A thorough understanding of the anatomy of the SVN might lead to significant benefits in therapy of discogenic low back pain. We suggest blocking the SVN at the level of the inferior vertebral notch of two adjacent segments. Level of evidence I Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding

PurposeAmong the few studies that have examined the development of the anterior abdominal wall, several are based on incomplete “series”, substituted in many cases by non-human specimens.Material and MethodsIn total, 19 human embryos corresponding to Carnegie stages 15–23, 36 fetuses with estimated gestational ages ranging from 9 weeks to term, and eight neonates were included in this study. All specimens belong to the collection of the Department of Anatomy and Embryology at the Complutense University of Madrid.ResultsThe muscles of the anterior abdominal wall appear in the dorsal region at stages 15 and 16 (33–37 days). At stages 17 and 18 (41–44 days), this muscular mass grows ventrally and splits into two sheets: the external abdominal oblique muscle and the common mass of the internal abdominal oblique, and the transversus abdominis muscles, all of which end ventrally in the primitive condensation of the rectus abdominis. In embryos at stages 19 and 20 (48 days), the anterior abdominal wall continues to show an umbilical hernia in the amniotic cavity. However, a narrow neck is apparent for the first time and there is a wider anterior abdominal wall below the hernia made up of dense mesenchyme tissue without layers and showing the primordia of the umbilical canal. In embryos at stages 21, 22, and 23 (51–57 days), the abdominal muscles and aponeuroses cross the midline (linea alba) covering the rectus abdominis and pyramidalis muscles while the umbilical hernia has shrunk. In fetuses during the 9th and 10th weeks, the umbilical hernia becomes encircled by the rectus abdominis muscle, its aponeurosis, and the three layers of lateral abdominal muscles, which are more developed and covered by Camper's and Scarpa's fasciae. The inguinal canal has a course and relationships like those described in adults, with Hesselbach's ligament.

Unfortunately, the 9th author name was incorrectly published in the original publication. The complete correct name should read as follows.Jose BouzadaThe original article has been corrected.Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.