The digestive system
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
Gastrointestinal activity is also modified by extrinsic autonomic nerves. The tract is innervated by both the parasympathetic and the sympathetic divisions of the autonomic nervous system. Parasympathetic innervation is provided primarily by the vagus nerves (esophagus, stomach, pancreas, gallbladder, small intestine, and upper large intestine) and the pelvic nerves (rest of the large intestine). Sympathetic innervation is provided by pathways that pass through the celiac, inferior mesenteric, and superior mesenteric ganglia. The effects of these two divisions tend to oppose each other. The parasympathetic system stimulates most digestive activities, whereas the sympathetic system inhibits them. Interestingly, the autonomic nerves to the digestive system, especially the vagus nerve of the parasympathetic system, can be discretely activated. In this way, digestive activity can be modified without affecting tissue function in other regions of the body.
Neural Control of the Intestinal Circulation and its Interaction With Autoregulation
Irving H. Zucker, Joseph P. Gilmore in Reflex Control of the Circulation, 2020
Origin and Distribution of Parasympathetic Innervation. Parasympathetic nerves to the digestive organs arise as preganglionic fibers from the cranial (VII, IX, and X) and sacral (S2–S4) portions of the spinal cord. The VII and IX cranial nerves supply the salivary glands, whereas the X cranial nerve (Vagus) supplies the majority of the visceral organs. The sacral parasympathetic outflow is contained in the pelvic nerve that distributes nerve fibers to the colon and bladder. Preganglionic parasympathetic nerve fibers enter the digestive organs to form synapses with the extensive enteric neurons of the myenteric or submucosal nerve plexi. The neurotransmitter at this synapse is acetylcholine. Postganglionic fibers also utilize acetylcholine as a neurotransmitter. Although parasympathetic nerves are recognized to play an important role in regulation of gastrointestinal function, their role in vasoregulation has been less clear.
Integrative Attachment Informed Cognitive Behavioral Play Therapy (IAI-CBPT) for Children With Medical Trauma
Lawrence C. Rubin in Handbook of Medical Play Therapy and Child Life, 2017
For children with medical trauma, medical problems, and pain, relaxation techniques are helpful. Pain can be reduced with relaxation techniques. Relaxation also helps the child relax physiologically, which reduces stress and, indirectly, pain. Psychoeducation about sensory experience and affect/memory/thoughts can be helpful. The parasympathetic nervous system responds to relaxation with decreased breathing rate, heart rate, body temperature, and blood pressure. Cortisol levels change related to relaxation exercises. Immune response is facilitated with relaxation. Psychoeducation may include the therapist, parent, and child discussing associations and how experiencing the sensation or even thinking about them can improve mood. Examples that may be given are feeling happy when smelling cookies or pumpkin pie, or feeling scared when smelling ‘hospital smell,’ calm when petting the child’s dog, or soothed from a specific type of touch (i.e., scratching or firm rubbing but not soft or tickly touch). Practicing evoking the sensory memory can be helpful.
Impact of passive heat stress on persons with spinal cord injury: Implications for Olympic spectators
Published in Temperature, 2020
Michelle B. Trbovich, John P. Handrakis, Nina S. Kumar, Mike J. Price
In addition to the motor and sensory interruption typically quantified and classified by the International Standards for Neurological Classification after Spinal Cord Injury (ISNCSCI) exam [27–29], SCI also disrupts sympathetic nervous system (SNS) pathways between the hypothalamic temperature control center within the brain (i.e. pre-optic area) and periphery. Meanwhile, parasympathetic nervous system (PNS) control remains largely intact. Consequently, the autonomic nervous system (ANS) is left in a predominant state of unopposed parasympathetic innervation. The imbalance of a predominately active PNS and hypoactive SNS perturbs cardiovascular and thermoregulatory homeostasis [30,31]. More specifically, under heat stress conditions, neural control of Tcore cooling mechanisms, namely, convective cooling through cutaneous vasodilation and evaporative cooling via sweating are both impaired following SCI [32,33]. Such impairment of SNS control of the skin vasculature and sweat glands after SCI increases the risk of hyperthermia and the potential life-threatening sequela from heat exhaustion and heat stroke (i.e. syncope, arrhythmias, dehydration, hematuria, seizures, delirium, loss of consciousness) [34–36].
Neuropathogenesis of HIV and emerging therapeutic targets
Published in Expert Opinion on Therapeutic Targets, 2022
Alina Siddiqui, Celestine He, Gina Lee, Alex Figueroa, Alexander Slaughter, Jessica Robinson-Papp
Acetylcholine is the main neurotransmitter of the parasympathetic nervous system and is also used by preganglionic neurons within the SNS. Acetylcholine is degraded in synapses by acetylcholinesterase, thus peripherally acting acetylcholinesterase inhibitors, such as pyridostigmine, have been proposed as a means of augmenting neurotransmission in autonomic neuropathies. Our group conducted a pilot study of pyridostigmine in PLWH treated with cART who had small intestinal bacterial overgrowth (SIBO), which is a common correlate of autonomic neuropathy in HIV presumably due to alteration of motility and immune function in the gut. We found that pyridostigmine substantially decreased SIBO as well as plasma levels of the inflammatory biomarkers TNFα and sCD14 [127]. Additionally, other investigators have demonstrated that the addition of pyridostigmine to cART significantly increased CD4+ T-cells [128].
Quantitative Evaluation of Pupil Responses in Patients with Prolactinomas Being Treated with Dopamine Agonists
Published in Neuro-Ophthalmology, 2022
Sedat Ava, Leyla Hazar, Mine Karahan, Seyfettin Erdem, Mehmet Emin Dursun, Zafer Pekkolay, Uğur Keklikçi
Normally, pupil responses are controlled by the autonomic nervous system. In the function of the PNS, acetylcholine as a neurotransmitter causes miosis in the pupil by stimulating the muscarinic receptors in the circular muscles of the iris, while in the function of the SNS, mydriasis occurs in the pupil when noradrenaline as a neurotransmitter stimulates the α-adrenergic receptors in the radial muscles of the iris.16 Sympathetic innervation is provided by the ipsilateral hypothalamus, while parasympathetic innervation is provided by the Edinger–Westphal nucleus located in the upper midbrain.17 Pupil responses normally reflect a balance between the SNS and PNS (between noradrenaline and acetylcholine) in the autonomic nervous system. In static pupillary function tests, PDs in dark environments show SNS function, whereas PDs in light environments show PNS function. Conversely, while the dilatation status (velocity and amplitude) of the pupil in dynamic tests indicates SNS function, the contraction status of the pupil (velocity and amplitude) indicates PNS function.
Related Knowledge Centers
- Autonomic Nervous System
- Defecation
- Enteric Nervous System
- Urination
- Sympathetic Nervous System
- Digestion
- Sexual Arousal
- Saliva
- Tears
- Fight-Or-Flight Response