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Review of the Human Brain and EEG Signals
Published in Teodiano Freire Bastos-Filho, Introduction to Non-Invasive EEG-Based Brain–Computer Interfaces for Assistive Technologies, 2020
Alessandro Botti Benevides, Alan Silva da Paz Floriano, Mario Sarcinelli-Filho, Teodiano Freire Bastos-Filho
The somatic motor system (SMS) and vegetative nervous system (VNS) are all neural references of CNS. The brain sends signals for muscle control and receives sensory information through 12 pairs of cranial nerves and 31 pairs of nerves in the spinal cord (Figure 1.7a). Axons that carry stimulatory signals from the brain to effector organs, such as muscles and glands, through the spinal cord, are primary efferent12 nerves of the SMS. Primary nerves enter the spinal cord through ventral roots. Axons that carry information from the sensory receptors of the skin, muscles, and joints to the brain, through the spinal cord, are the primary afferent13 nerves of the somatic sensory system, which enter the spinal cord through dorsal roots. Thus, the two roots of the spinal cord transmit information in opposite directions [1].
The Spinal Cord and the Spinal Canal
Published in Bernard J. Dalens, Jean-Pierre Monnet, Yves Harmand, Pediatric Regional Anesthesia, 2019
Bernard J. Dalens, Jean-Pierre Monnet, Yves Harmand
Spinal nerves are formed by the union of ipsilateral dorsal and ventral roots issuing from the same spinal segment. They rapidly divide into four branches (Figure 1.35): meningeal ramus, dorsal ramus (or posterior primary ramus), ventral ramus (or anterior primary ramus), and ramus communicans.
The nervous system
Published in Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella, Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella
The dorsal root contains afferent, or sensory, neurons. Impulses in these neurons travel from peripheral tissues toward the spinal cord. The dorsal root joins the spinal cord laterally, toward the posterior surface of the cord (Figure 13.5). The ventral root contains efferent, or motor, neurons. Impulses in these neurons travel away from the spinal cord toward the peripheral tissues. The ventral root exits the spinal cord laterally, toward the anterior surface of the cord.
Clinical significance of cervical MRI in brachial plexus birth injury
Published in Acta Orthopaedica, 2019
Petra Grahn, Tiina Pöyhiä, Antti Sommarhem, Yrjänä Nietosvaara
Altogether 170 root levels were examined. 18 total root avulsions were detected in 12/34 patients (Figure 1). 6 patients had partial avulsions only (dorsal root 2, ventral root 5) (Figure 2). 4 patients with total or partial root avulsions also had thinning of additional roots (Figure 3, Table 1). The most extensive injury was in patient number 8, who had total avulsions of C6–8 with thinning of both the ventral and dorsal C5 rootlets. The number of totally avulsed roots per patient varied from 1 to 3. The most commonly totally avulsed root was C8. Sensitivity and specificity of MRI in detecting total root avulsions was 0.88 (CI 0.5–1) and 1 (CI 1–0.9). PMC was seen in association with all 18 total root avulsions, and in 6 of the 8 partial avulsions at the level of the avulsion. 2 patients had PMC without evidence of root injuries (Figure 4). Specificity and sensitivity of PMC for total nerve root avulsion was 0.44 and 1.
Neurological complications of Zika virus infection
Published in Expert Review of Anti-infective Therapy, 2018
Arthrogriposis and other osteoarticular malformations have been seen in severe cases and were associated with poor intrauterine movement and thinning of spinal cord. A neurogenic origin with secondary involvement or motor neurons has been proposed. Arthrogriposis can happen following degeneration of long descending tracts and motor neurons of corticospinal tract in spinal cord and brainstem, causing decreased fetal movements and even akinesia, and fixed postures and deformities [38,39]. Thinning of spinal cord and reduced ventral roots has been seen on spine MRI in CZS patients having arthrogryposis [40]. Other orthopedic abnormalities include hip dislocation, clubfoot, camptodactyly, and contractures with flexed wrist and fingers [41].
Disruption of the network between Onuf’s nucleus and myenteric ganglia, and developing Hirschsprung-like disease following spinal subarachnoid haemorrhage: an experimental study
Published in International Journal of Neuroscience, 2019
Ozgur Caglar, Binali Firinci, Mehmet Dumlu Aydin, Erdem Karadeniz, Ali Ahiskalioglu, Sare Altas Sipal, Murat Yigiter, Ahmet Bedii Salman
According to the classic understanding of the autonomic innervation of human in the lower abdomen, parasympathetic ganglion cells are located near the pelvic viscera and in the pelvic plexus, whereas sympathetic ganglion cells exist along the lumbar and sacralsympathetic trunks [11]. Affection of these nerves lead to sexual and sphincter dysfunction in human [11]. This dysfunction seems to be dependent to damage to the hypogastric nervous plexus. The superior and inferior hypogastric plexuses receive input from sympathetic preganglionic fibres whose cell bodies reside in the intermediolateral cell columns of the lower spinal cord. Same mechanism may be responsible in Hirschprung Disease. The superior and inferior hypogastric plexuses receive input from sympathetic preganglionic fibres whose cell bodies reside in the intermediolateral cell columns of the lower spinal cord [12] or the sacral spinal cord. This cell group was first described in 1899 by Onufrowicz and became as known as Onuf's nucleus. These efferent, preganglionic fibres first leave the spinal cord via the ventral roots of spinal nerves and exit the spinal nerves via the white rami communicantes into the lumbosacral sympathetic chain [12]. Onuf’s nucleus is localized mainly in S3–4 segments. It is composed of organized medium-sized neurons and located in the ventrolateral aspect of the ventral horn of the first sacral segment. Onuf’s nucleus has different cortical afferent connections with contralateral corticospinal tract fibres [13] and contains motorneurons that innervate the pelvic floor muscles, including the external urethral and anal sphincters, and manage micturition, vomiting, defecation, and parturition reflexes [14].