Textbooks suggest that there S2, S3, and S4 regions of the spinal cord contain preganglionic nulcei in the anterior grey horn. However, there is no grey horn in the sacral region, as the cord itself ends by L2. Also Espinosa-Mendina et al (Science 354 893-897, 2016) found genetic signatures of sympathetic neurons in the sacral output, not parasympathetic. They have redrawn the ANS accordingly.
Wouldn't the sacral output (say pelvic nerve etc) have their nuclei in L1 or L2?
Look into Kinder MV et al. The neuronal control of the lower urinary tract: A model of architecture and control mechanisms. Arch Physiol Biochem (1999) 107:203-222 and - Neuronal circuitry of the lower urinary tract; central and peripheral neuronal control of the micturition cycle. Anat Embryol (1995) 192:195-209
Professor, it’s a common mistake identify the vertebral segments with the segmentation of the spinal cord. It is correct to say that the spinal cone or conus medularis is at the level of L1-L2 vertebral segments in humans approximately, but these segments are the so called sacral segments of the spinal cord(see figure in the link, 1) and of course they cointain neurons for striated and smooth muscles, and parenchyma. Consider aswell that in Albino Rat, the conus medularis is at L3-L4 If you’re working with this animal model.
(1) https://images.app.goo.gl/1sj2dLizTLotUvRR9
Vertebral and spinal segment correlation will work, i guess. Sacral outflow parasympathetic, preganglionic secretes ach at ganglionic side, postganglionic long fiber via specific receptor to end organ. Conus will represent the sacral segments
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