The “sacral parasympathetic”: ontogeny and anatomy of a myth

Figures

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  Fig. 1. Schematics of the autonomic innervation of the pelvis. a Schematic of the projection of the spinal cord (spinal nerves T12, L1, L2, S2 and S3) to the lumbar and sacral autonomic ganglia. The pelvic ganglion receives a dual input, thoraco-lumbar through the hypogastric nerve, and sacral from the pelvic nerves. The sacral paravertebral chain does not receive projections (rami communicantes) from the sacral cord. Abbreviations: HGN hypogastric nerve, IMG inferior mesenteric ganglion, PG pelvic ganglion, PN pelvic nerve, CPN common pelvic nerve, LSpl lumbar splanchnic nerves, RC ramus communicans, SC spinal cord, PV paravertebral chain. b Schematic of the cranio-sacral division by Gaskell [11]: no pelvic ganglion is shown, and the extra-mural neurons postganglionic to the pelvic nerves are represented exactly like the intramural ones postganglionic to the vagus nerve. c Kuntz [31] represents the pelvic ganglion as a purely parasympathetic relay, devoid of lumbar connection, 10 years after his own description of a dual input [5]. d The 24th edition of Gray’s anatomy (1948) omits the pelvic ganglion on the path of the pelvic nerve. This is unchanged in recent editions [9]. e Testut and…

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  Fig. 2. Connections between the spinal cord and the sympathetic chain, as originally described by Gaskell: Fig. 4 from [11] showing (in black) the white ramus comunicans from the spinal cord (which would be on the right of the figure, not shown) through the ventral roots of the second thoracic (D2) to third lumbar (L3) nerves, but neither rostrally nor caudally from there. Neither the superior cervical ganglion (S.C.G.) nor the sacral ones (S1 and below) receive input from their rostro-caudal level, but rather from the thoracolumbar cord below or above, respectively, via longitudinal projection through the paravertebral chain. The projections from sympathetic ganglia to the spinal nerves (grey rami communicans) are shown in red. A.V. annulus of Vieussens (or subclavian loop), R.V. ramus vertebralis, St.G. stellate ganglion

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  Fig. 3. Semi-schematic representation of the pelvic nerves from Testut and Latarjet, 9th edition [8]: the pelvic nerves (labeled 14, in red] emanating from the third and fourth sacral nerves (SIII and SIV) directly project to the pelvic ganglion (labeled 13, in blue) while completely bypassing the sacral paravertebral chain (labeled 10 and connected to the spinal nerves by one or two grey rami communicantes, unlabeled on the figure). Other numbers refer to the coccygeal plexus (9), presacral nerve (anterior hypogastric plexus) (11), hypogastric nerves (12), efferent branches of the pelvic ganglion (15), ganglion of Walther (ganglion impar) (16), branch of sacral sympathetic contributing to the meningeal nerve (18)

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  Fig. 4. Response of the bladder to stimulation of the hypogastric nerve according to a Elliott [29] in cats (but not most other species), isometric pressure record. Note that “as the lever writes on an arc of great curvature, at the top of the tracing it is much to the left of the vertical line through the signal”; b Stewart [30], in cat, kymographic record, bar: 10 s; c Kuntz, kymographic record (reproduced in [31], bar: 40 s; d Fagge [32], in dog, isometric pressure curve, stimulation of the pelvic nerve (s) and hypogastric (h), the latter eliciting only a slight contraction