Control of blood vessels: extrinsic control by nerves and hormones
Neil Herring, David J. Paterson in Levick's Introduction to Cardiovascular Physiology, 2018
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
J. Richard Smith, Giuseppe Del Priore, Robert L. Coleman, John M. Monaghan in An Atlas of Gynecologic Oncology, 2018
Few procedures require a complete dissection of nerves in gynecologic oncology, although this is advocated by some investigators. Larger nerves are sometimes used as landmarks during surgical dissections; for instance, the obturator nerve may serve as the near-to-inferior border of pelvic lymphadenectomy (obturator fossa) and the phrenic nerve as the posterior border of the scalene node dissection. Smaller nerves, such as the genital femoral nerve, may be transected during the removal of suspicious lymph nodes. To avoid injury, at the very beginning of a surgical procedure, the anatomy of the nervous system should be kept in mind when positioning the patient. For example, because laparoscopy requires the surgeon to be further cephalad than during the same procedure done by laparotomy, both arms should be tucked at the patient’s side to avoid excessive superior traction on the brachial plexus. During vaginal procedures, resting an arm on the medial anterior thigh may compress the femoral nerve. This nerve may also be injured by an abdominal retractor placed too deeply over the psoas muscle. Further, the sympathetic trunk and hypogastric nerves are responsible for sympathetic innervation of the pelvis. Injury to the sympathetic trunk can cause ipsilateral vasodilatation postoperatively (hyperthermia in the lower extremity). The splanchnic nerves carry parasympathetic innervation of the pelvis and control micturition and defecation. The nerves of the pelvis and abdomen show a wide spectrum of variation in topographic anatomy. Nevertheless, the general course and function of many nerves must be known in order to avoid their injury and minimize surgical complications (Figures 4.8 and 4.9).
Reflex Effects From Abdominal Visceral Afferents
Irving H. Zucker, Joseph P. Gilmore in 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%).
The Vagus Nerve and the Celiaco-mesenteric Ganglia Participate in the Feeding Responses Evoked by Non-sulfated Cholecystokinin-8 in Male Sprague Dawley Rats
Published in Endocrine Research, 2020
Amged I. Dafalla, Thaer R. Mhalhal, Kenneth Hiscocks, John Heath, Ayman I. Sayegh
The vagus nerve comprises the main parasympathetic innervation of the gastrointestinal tract, with cell bodies located in the nodose ganglia (the sensory/afferent portion) and the dorsal motor nucleus of the vagus (DMV, the motor/efferent portion).9,10 The splanchnic nerve comprises the main sympathetic innervation of the gut and also contains visceral afferent and efferent fibers. The cell bodies of the first-order neurons of this nerve reside in the pre – and paravertebral ganglia along the spinal cord, whereas the cell bodies of the second-order neurons reside in the celiaco-mesenteric ganglia, located between the celiac and the cranial mesenteric arteries.11,12 Although both nerves contain efferent and afferent fibers, the majority of these fibers are afferents e.g. over 85% of the fibers in the vagus nerve are afferents.9,10,13,14
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.
Sex differences in the hypothalamic-pituitary-adrenal axis response following a single or multiple days of sleep restriction
Published in Stress, 2020
Katelyn N. Buban, Elizabeth A. Shupe, Stephen W. Rothwell, T. John Wu
The splanchnic nerve is known to promote the release of corticosterone from the adrenal glands via its vasoactive intestinal peptide (VIP)-ergic projections (Bornstein, Ehrhart-Bornstein, Scherbaum, Pfeiffer, & Holst, 1990; Ehrhart-Bornstein, Bornstein, Scherbaum, Pfeiffer, & Holst, 1991). Similarly, autonomic noradrenergic projections have also been shown to elicit the release of CORT from the adrenal glands (Bornstein et al., 1990). Past studies have reported increases in catecholamines such as norepinephrine following a prolonged period of sleep deprivation, which drop below control levels following a period of sleep recovery (Andersen et al., 2005). Therefore this dysregulation might be occurring at a higher level through changes in catecholaminergic and/or VIP-ergic projections from the sympathetic nervous system. The changes in enzyme mRNA expression seen here might be a sex-dependent compensatory mechanism by the adrenals to increase the bioavailability of CORT to the animal’s system post-PSD. Further studies exploring splanchnic nerve activation and VIP and norepinephrine expression/release in the adrenals are necessary to fully understand how the sympathetic system might be contributing to the blunted HPA axis reactivity observed in the present study.
Related Knowledge Centers
- Autonomic Nervous System
- Pelvic Splanchnic Nerves
- Sensory Nerve
- Sympathetic Nervous System
- Parasympathetic Nervous System
- General Visceral Efferent Fibers
- General Visceral Afferent Fiber
- Cardiopulmonary Nerves
- Thoracic Splanchnic Nerves
- Lumbar Splanchnic Nerves