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Spinal CordAnatomical and Physiological Features
Published in Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal, Principles of Physiology for the Anaesthetist, 2020
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal
The spinal cord is a long, thin tubular structure which is continuous with the caudal part of the medulla and is enlarged in the cervical and lumbar regions. The cervical enlargement stretches from C4 to T1 vertebrae and handles sensory input and motor output to the upper limbs. The lumbar enlargement, located between L2 and S3, corresponds to the lumbar plexus and handles sensory input and motor output to the lower limbs.
Specific Synonyms
Published in Terence R. Anthoney, Neuroanatomy and the Neurologic Exam, 2017
Lower enlargement (M&M, p. 15) Lumbar enlargement (C&S, p. 232)Lumbosacral enlargement (B&K, p. 63–64)Lumbosacral intumescence (MarMar, p. 87)
Anatomical considerations
Published in Hemanshu Prabhakar, Charu Mahajan, Indu Kapoor, Manual of Neuroanesthesia, 2017
The spinal cord begins as a continuation of the medulla oblongata at the foramen magnum and terminates at the level of the lower border of the first lumbar vertebra in adults. In children, it extends to the upper border of the third vertebra. In the cervical and lumbar regions, the cord is expanded into fusiform shape and is known as the cervical and lumbar enlargement, respectively. The lower end of the cord tapers to form conus medullaris. The dura and arachnoid mater along with the subarachnoid space containing CSF extend beyond the lower end of the cord up to the second sacral vertebra. The pia mater extends below the conus medullaris to form the filum terminale that ends by attaching to the first coccyx vertebra.6 Thirty-one pairs of spinal nerves are attached to the spinal cord by the anterior or ventral (motor) roots and posterior or dorsal (sensory) roots. Each posterior root has a ganglion (dorsal root ganglion) that contains cells giving rise to peripheral and central nerve fibers. Internally, the spinal cord has a core of gray matter surrounded by white matter. The butterfly-shaped gray matter has dorsal and ventral projections or horns (Figure 1.8). In the center of the spinal gray matter lies the vestigial ventricular system, the central canal.6
The pathological involvement of spinal cord EphB2 in visceral sensitization in male rats
Published in Stress, 2022
Tao Chen, Si Chen, Xuefeng Zheng, Yaofeng Zhu, Ziyun Huang, Linju Jia, Lisi OuYang, Wanlong Lei
Rats were implanted with an indwelling intrathecal catheter to facilitate delivery of the drug or its vehicle intrathecally. The rats were anesthetized by intraperitoneal injection of 2% sodium pentobarbital (50 mg/kg). The gap between L4 and L5 was exposed, and a 25 G needle was inserted into the intrathecal space between L4 and L5 until a tail-flick was elicited, confirming intrathecal placement. A 75% alcohol-flushed polyethylene (PE-10) tube was then inserted 2 cm deep to ensure that the tip was located at the ideal position for spinal lumbar enlargement. The other end of the catheter extending out the back of the neck, and the skin was closed with 2-0 sutures. After awakening, rats were excluded from the study if they showed bilateral lower-limb paralysis, which indicated spinal cord injury. These rats were used in the SPS experiment at the scheduled time after surgery. The rats not included in this study were anesthetized with pentobarbital sodium (intraperitoneal, 50 mg/kg) and euthanized by cervical dislocation.
Perforin affects regeneration in a mouse spinal cord injury model
Published in International Journal of Neuroscience, 2021
Igor Jakovcevski, Melitta Schachner
Cell counts were performed on an Axioscope microscope (Zeiss) equipped with a motorized stage and Neurolucida software-controlled computer system (MicroBrightField) using the optical disector method, as described [35,42]. Coronal spinal cord sections from the 1.5-mm-long segment starting at the caudal side of the lumbar enlargement, thus comprising almost the complete lumbar spinal cord, were used for counting. The sections were examined under low-power magnification (10x objective) with a 365/420 nm excitation/emission filter set (01, Zeiss, blue fluorescence). The nuclear staining allowed the delineation of spinal cord gray and white matter areas. Numerical density of Iba-1+ and GFAP + cells was estimated by counting nuclei of immunolabeled cells within systematically spaced optical disectors. The parameters for this analysis were: guard space depth 2 μm, base and height of the disector 3600 μm2 and 10 μm, respectively, distance between the optical disectors 60 μm, using the Plan-Neofluar 40/0.75 objective. Left and right spinal cord areas were evaluated in six sections 250 µm apart each. All results shown are averaged bilateral values.
Congenital Spinal Lipomatous Malformations. Part 2. Differentiation from Selected Closed Spinal Malformations
Published in Fetal and Pediatric Pathology, 2021
The postnatal medullary spinal cord, found occasionally in children and adults, is a thick, retained remnant of the secondary neural cell mass extending caudal to the S2 spinal level. A retained medullary cord has the gross appearance of an elongated conus medullaris caudal to the lumbar enlargement. Regression in this elongated conus-like tissue is not always even. In one patient, the spinal cord tapered at L3 into a thick, filum-like band that expanded at S1 into neural tissue and ended with a small central cavity described as a presacral cyst. Intraoperative electrophysiological monitoring can map out the functional conus rostral to the elongated medullary cord, the latter being electrophysiologically silent [11, 12].