Discussions (D)
Terence R. Anthoney in Neuroanatomy and the Neurologic Exam, 2017
If one knows what a term containing the word “spinal” means, then it probably doesn’t matter what the referent for “spinal” is. But if one doesn’t, one could be misled. For example, “spinal injury” could reasonably mean injury to the spinal column or to the spinal cord. Usually, however, it refers to a cord injury (e.g., Rowl, p. 300), as opposed to the term “spine injury,” which refers to a column injury (e.g., Rowl, p. 302). The term “spinal nerve” provides another example. One might think that a spinal nerve is any nerve the arises from the spinal cord. However, the spinal accessory nerve, which arises partially or wholly from the cord (see D: Accessory nerve for details), is considered solely a cranial nerve, presumably because it exits the axial skeleton through the cranium. This suggests that the “spinal” in “spinal nerve” refers to the spinal column—through which spinal nerves exit the axial skeleton. As yet another example, “spinal stenosis” could mean a narrowing of the cord or of the column, but it doesn’t. Instead, it refers to a narrowing of the spinal canal (e.g., Rowl, p. 305). Other examples of terms with meanings that make the referent of “spinal” clear are “spinal shock” and “spinal concussion,” where the referent is the cord (e.g., Rowl, p. 300), and “paraspinal muscles,” where the referent is the column (e.g., Rowl, p. 305).
Sources Of Dopamine In Peripheral Tissues
M.D. Francesco Amenta in Peripheral Dopamine Pathophysiology, 2019
Spinal nerves are formed by axons reaching the spinal cord via ventral (motor) and dorsal (sensory) roots. While somatic and autonomic (preganglionic) motor axons coming from ventral roots are cholinergic, sensory neurons entering the spinal cord via dorsal roots probably use substance P or somatostatin as neurotransmitters.64,65 Starting from the observation of catecholamine histofluorescence in ventral nerve roots of rat spinal cord,66 evidence has been obtained that ventral roots in animals and man are richer in DA than in norepinephrine.35 Especially high levels of dopamine and norepinephrine have been found in ventral roots of thoracic nerves.67 More recently, histofluorescence and immunohistochemical studies revealed the presence of small DA-containing neurons in sensory ganglia. These small neurons (about 20 μm in diameter) were distributed throughout the entire ganglion, representing about 1% of the total sensory neurons in the L5 ganglion.68 These data on the whole support the view that dopaminergic neurons and/or nerve fibers in the peripheral nervous system are not necessarily related to the sympathetic nervous system.
The nervous system
Laurie K. McCorry, Martin M. Zdanowicz, Cynthia Y. Gonnella in Essentials of Human Physiology and Pathophysiology for Pharmacy and Allied Health, 2019
The spinal cord is divided into four anatomical regions: cervical, thoracic, lumbar, and sacral. These regions are named according to the vertebrae adjacent to them during embryonic development. Each region is further subdivided into 31 functional segments: 8 cervical (C) segments, 12 thoracic (T) segments, 5 lumbar (L) segments, 5 sacral (S) segments, and 1 coccygeal (Co) segment. A pair of spinal nerves extends from each segment, with 1 nerve from the left side of the spinal cord and 1 nerve from the right side. Spinal nerves exit the CNS through the intervertebral foramina, or openings, between adjacent vertebrae. There are 31 pairs of spinal nerves: 8 cervical12 thoracic5 lumbar5 sacral1 coccygeal
Communication between the gut microbiota and peripheral nervous system in health and chronic disease
Published in Gut Microbes, 2022
Tyler M. Cook, Virginie Mansuy-Aubert
Neuronal transmission allows for nearly instantaneous processing of sensory input or generation of motor output. This rapid signaling of peripheral neurons in the gut is critical for homeostatic mechanisms such as GI motility, secretion, and even immune response modulation.39 The peripheral nervous system (PNS) consists of vagal and spinal sensory (afferent) neurons, autonomic motor (efferent) neurons, and enteric neurons (Figure 2). Afferent neurons send information from the periphery to the brain or spinal cord, while efferent neurons project out from the central nervous system (CNS) to peripheral organs. Classifying by anatomical distribution, the twelve cranial nerves project from the brain/brainstem and spinal nerves from the spinal cord. The autonomic system is divided into sympathetic, parasympathetic, and enteric nervous systems (ENS).
Buyang Huanwu decoction improves neural recovery after spinal cord injury in rats through the mTOR signaling pathway and autophagy
Published in The Journal of Spinal Cord Medicine, 2023
Ying Nie, Yujie Fan, Xi Zhang, Xiaosong Li, Jian Yin, Meili Li, Zhaoyong Hu, Liang Li, Xiaoye Wang
RST transection model is often used in SCI repair research because of its clear bundle, simple operation, and small trauma. The RST transection operation was performed following the methods described before.3 Rats were anesthetized by intraperitoneal injection of 2% pentobarbital sodium (30 mg/kg), the cervical curvature was fixed in the prone position, and the soft tissue and superficial muscles were separated under the operating microscope. Part of the erector spinae attached to the right side of the C2 spinous process was removed to expose the ligamenta flava between the C3 and C4 vertebral arches, and the ligamenta flava was cut open to expose the spinal cord. A small incision was made through the dura mater following identifying the dorsal root of the spinal nerve. Then, the right dorsolateral funiculus of the spinal cord was transected using a No. 12 surgical blade. This operation completely transected the lateral funiculus (containing the RST) and partially injured the ipsilateral ventral funiculus and gray matter, leaving the dorsal columns intact. When the animal woke up, the right forelimb was flexed and close to the trunk, with uncoordinated movement, and the right forepaw could not open, indicating the success of the operation.
Translational issues in precision medicine in neuropathic pain
Published in Canadian Journal of Pain, 2020
Anthony H. Dickenson, Ryan Patel
Thus, overall, ongoing activity in primary afferent fibers drives spontaneous thalamic firing after spinal nerve injury and oxcarbazepine exhibits modality-selective inhibitory effects on sensory neuronal processing through a peripheral mechanism. These inhibitory effects of both lidocaine and oxcarbazepine suggest that this rat model of neuropathy, involving a partial ligation of spinal nerves, resembles the irritable nociceptor patient subgroup. Baron and colleagues proposed that these patients are represented within the thermal cluster and that peripheral sensitization is the predominant pathophysiological mechanism.5 Spinal nerve injury in rats produces a profile of sensory gain in a manner that resembles the thermal and mechanical phenotypes in patients but has little likeness to the sensory loss group.14
Related Knowledge Centers
- Cervical Vertebrae
- Lumbar Vertebrae
- Thoracic Vertebrae
- Spinal Cord
- Vertebral Column
- Coccyx
- Sacrum
- Mixed Nerve
- Body
- Nerve