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Reflex Effects From Abdominal Visceral Afferents
Published in Irving H. Zucker, Joseph P. Gilmore, Reflex Control of the Circulation, 2020
The splanchnic nerve contains a large number of sympathetic afferents. The ratio of afferent to efferent fibers in this nerve is 3:1 (Leek, 1977). Other important sources of afferent spinal nerves from the abdominal region include the hypogastric, lumbar, colonic, and pelvic nerves. There are approximately 22,000–25,000 spinal abdominal and pelvic afferent nerves in the cat amounting to 1.5–2.5% of the total spinal afferent input (Jänig and Morrison, 1986). Splanchnic afferents are comprised of approximately equal numbers of myelinated and unmyelinated axons (54% vs. 46%), whereas the vagus contains mostly unmyelinated afferent fibers (99%).
Control of blood vessels: extrinsic control by nerves and hormones
Published in Neil Herring, David J. Paterson, Levick's Introduction to Cardiovascular Physiology, 2018
Neil Herring, David J. Paterson
During embryogenesis, the medullary chromaffin cells develop from postganglionic sympathetic neurons. This accounts for their innervation by preganglionic sympathetic fibres in the splanchnic nerve (Figure 14.1). Sympathetic activity thus regulates adrenaline secretion. Secretion is stimulated in response to four main stresses, namely:exercise;alerting (the alerting response to ‘fight or flight’ situations);hypotension; andhypoglycaemia.
Anatomy
Published in Jonathan M. Fishman, Vivian A. Elwell, Rajat Chowdhury, OSCEs for the MRCS Part B, 2017
Jonathan M. Fishman, Vivian A. Elwell, Rajat Chowdhury
The adrenal gland comprises an outer cortex and an inner medulla, which represent two developmentally and functionally independent endocrine glands within the same anatomical structure. The medulla is derived from the neural crest (ectoderm). It receives preganglionic sympathetic fibres from the greater splanchnic nerve and secretes adrenaline (70%) and noradrenaline (30%). The cortex is derived from mesoderm and consists of three layers or zones. The layers from the surface inwards may be remembered by the mnemonic GFR: G = Zona glomerulosa (secretes aldosterone)F = Zona fasciculata (secretes cortisol and sex steroids)R = Zona reticularis (secretes cortisol and sex steroids)
The neural pathway of the hyperthermic response to antagonists of the transient receptor potential vanilloid-1 channel
Published in Temperature, 2023
Andras Garami, Alexandre A. Steiner, Eszter Pakai, Samuel P. Wanner, M. Camila Almeida, Patrik Keringer, Daniela L. Oliveira, Kazuhiro Nakamura, Shaun F. Morrison, Andrej A. Romanovsky
Bilateral splanchnicotomy. A midline laparotomy was performed, and the stomach and liver were deflected from the subdiaphragmatic area with saline-moistened gauze to expose the dorsal abdominal wall. On each side, the retroperitoneal space was opened, and the greater splanchnic nerve was isolated and cut, either as a single trunk or as two or more divisions, just beneath the diaphragm as in our earlier study [27]. In sham splanchnicotomy, the nerve was exposed on each side but not cut. The integrity of the greater splanchnic nerve is required for the modulation of adrenal responsiveness [28]. The adrenal splanchnic innervation is an additional mechanism controlling the production of corticosterone independently from adrenocorticotropic hormone, and splanchnichotomized rats were shown to express an attenuated corticosterone response to water deprivation [29]. To verify the completeness of splanchnicotomy, at the end of the experiments, rats were subjected to a 48-h water deprivation and then anesthetized, and their arterial blood was collected by cardiac puncture in a heparin-containing Vacutainer tube and centrifuged (3000 g, 10 min, 4°C). The plasma corticosterone concentration was measured by ELISA (Assay Designs).
Age-dependent changes in hormonal stress reactivity following repeated restraint stress throughout adolescence in male rats
Published in Stress, 2021
Russell D. Romeo, Rose K. Sciortino
It is important to note that, in addition to central mechanisms, peripheral mechanisms may also play a role mediating these age- and experience-dependent changes in HPA reactivity. For instance, we have previously shown pubertal changes in adrenal sensitivity to ACTH (Romeo et al., 2014) and our current data, in the context of the ratio of plasma corticosterone to the log of plasma ACTH, would support the idea that changes in adrenal sensitivity to ACTH and/or steroidogenic capability of the adrenal might contribute to the sensitized response following homotypic stress at this stage of development. Moreover, splanchnic nerve innervation of the adrenal gland might also contribute to some of these changes in hormonal stress reactivity, as has been noted in adult rats (Ulrich-Lai & Engeland, 2002). Future studies utilizing peripheral hormone administration paradigms and splanchnic nerve transection in animals exposed to homotypic stress would help elucidate this possibility.
Spinal cord involvement in Lewy body-related α-synucleinopathies
Published in The Journal of Spinal Cord Medicine, 2020
Raffaele Nardone, Yvonne Höller, Francesco Brigo, Viviana Versace, Luca Sebastianelli, Cristina Florea, Kerstin Schwenker, Stefan Golaszewski, Leopold Saltuari, Eugen Trinka
Fibers originating in the rostroventral nucleus of the medulla that traveling in the Th/IML provide the efferent innervation. Of great importance is also the capacitance of the splanchnic-mesenteric bed. This region is supplied by the splanchnic nerve with cell bodies at the thoracic level and synapses at the celiac ganglion.91 Orthostatic hypotension is a chief complaint in the pure autonomic failure, in LBD and in MSA. Some cases starting as isolated autonomic failure and subsequently developing PD or LBD features were described.71,92,93 Moreover, dysfunctions of cardiac sympathetic and parasympathetic neurons were observed in the initial stages of PD.93 Even is also the genesis of orthostatic hypotension is likely to be multifactorial, the pathology of the dorsal motor nucleus of the vagus may explain the early occurrence of orthostatic hypotension.