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Classification of peripheral nerves

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electrical stimulation of the sympathetic neurons, and other classes of drugs likewise elicited responses that were contained to the parasympathetic neurons. The sympathetic nervous system's responsiveness to adrenaline, in particular, lead to the system's association with the 'fight or flight' response of humans, although this is an oversimplification of the roles played by the SNS. These two distinct classifications were further supported by differences in the location of the ganglionic synapses. Since the time of Langley's unified proposal in the 1920s, these divisions have remained relatively constant; the parasympathetic nervous system is known to regulate unconscious activities of the body and maintain homeostasis, the sympathetic nervous system controls responses to external stimuli, but both are involuntary functions. Langley also described an enteric nervous system although it has received minimal attention, and most modern textbooks tend to only mention the sympathetic and parasympathetic pathways in the context of the autonomic nervous system.
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Espinosa-Medina. Jänig et al. argue that many of the measured gene markers from Espinosa-Medina are only expressed transiently in the lumbrasacral region to assist in migration and differentiation of these cells. As such, these nerves necessarily share expression similarities with their neighboring sympathetic spinal nerves, but that alone does not make the nerves anything more than spinal in nature. Furthermore, Jänig et al. state that this reclassification would contradict information on the opposing actions of the pelvic ganglia's parasympathetic and sympathetic pathways.
150:. These transcription factors were only identified within other portions of the spinal cord, but they were not co-expressed in the developing cranium. This genomic similarity of the lumbrasacral region to the rest of the spinal cord lead to the conclusion that the sacral region of the spinal cord may actually be part of the sympathetic nervous system. The effect of this revision produces a simple bisection of the autonomic nervous system wherein the cranium is solely parasympathetic, and the spinal cord is solely sympathetic. 231: 17: 108:
regions. The latter two, tectal and bulbo-sacral, were grouped together to form the parasympathetic system because they tended to respond in a like manner to various drugs. Langley also mentions an enteric nervous system in his writing, but this third grouping has largely fallen out of discussion in modern practice.
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The division of the autonomic nervous system into sympathetic and parasympathetic pathways is particularly useful from a medical treatment perspective . Jänig et al. warn that changing the classifications of the systems could result in confusion on how to treat some disease, particularly those of the
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reactions in another part of the body, as well as the "ganglionic nerves and ganglionic nervous system" for the ganglionic conversion of voluntary to involuntary movements (which supposedly made these peripheral nerves 'ganglionic nerves'), among other classifications. Langley stated that his choice
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region of the spine (roughly vertebrae T1-L3) whereas the parasympathetic system covers peripheral nerve synapses in the vertebrae regions of T12-S4 in addition to a number of cranial nerves. As can be noticed from this description, there is a slight overlap of these divisions in the lowest region
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the spinal cord and cranium made the 'ganglionic' connections of the peripheral nerves a pointless, if not misleading, term. Instead, he noted that the sympathetic neurons that innervated the entire body tended to have opposing functions to the other autonomic neurons of the tectal and bulbo-sacral
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Much of the original nerve classification done by Langley, and Gaskell by extension, was based on pharmacological responses of nerves throughout the body as well as the gross anatomical similarities of nerves. For example, adrenaline was demonstrated to elicit the same bodily effects as direct
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The nerve classifications of the autonomic nervous system created by the traditional methodologies have remained mostly unchanged over the last 100 years. However, modern perspectives have placed more of an emphasis on the developmental and molecular mechanisms of these systems. As such, more
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Other researchers in the field have challenged this assertion. A publication out of the lab of German researcher Wilfrid Jänig claims that this reclassification would be a 'mistake.' Among the arguments made by Jänig et al. is a disagreement with the developmental research approach taken by
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first coined the term "autonomic" in classifying the connections of nerve fibers to peripheral nerve cells. Previous researchers had utilized different terms such as "the sympathetic nerves" to describe the way in which neurons in one part of the body brought about
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was not intended to imply a special degree of independence for the cells at hand, but rather to demarcate a clear departure from previous nomenclature because his hypothesis, while incorporating much previous research, was largely distinct from his predecessors.
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Disregarding the current debate of changing the sacral outflow from parasympathetic to sympathetic, the divisions of the two systems are fairly straightforward; the sympathetic system encompasses those peripheral nerves that synapse along the
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attention has been paid to elements such as gene expression, development features, and overall functions of these neurons. The classification of the sacral outflow as parasympathetic, in particular, has come under some scrutiny as of 2016.
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Isabel Espinosa-Medina, working in the lab of French researcher Jean-François Brunet at IBENS, identified several transcription factors within pre-ganglionic neurons of the lower lumbar and sacral regions that are essential to
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region. This overlap is a result of some directly opposing functions of the sympathetic and parasympathetic systems in regulating the stomach region. The relationship is further detailed in the diagrams below.
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Jänig, Wilfrid; Keast, Janet R.; McLachlan, Elspeth M.; Neuhuber, Winfried L.; Southard-Smith, Michelle (2017-09-01). "Renaming all spinal autonomic outflows as sympathetic is a mistake".
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Langley rejected that the sympathetic nerves possessed a particular relationship to the 'sympathies,' and aptly pointed out that the presence of ganglial nerves in
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Espinosa-Medina, I.; Saha, O.; Boismoreau, F.; Chettouh, Z.; Rossi, F.; Richardson, W. D.; Brunet, J.-F. (2016-11-18).
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present outside of the spinal cord and brain. The somatic nervous system directs all voluntary movements of the
616: 65: 369:"On the Union of Cranial Autonomic (Visceral) Fibres with the Nerve Cells of the Superior Cervical Ganglion" 508:""Receptive Substances": John Newport Langley (1852–1925) and his Path to a Receptor Theory of Drug Action" 61: 29: 286: 37: 701:"Sympathetic inhibition of the urinary bladder and of pelvic ganglionic transmission in the cat" 570:"The Innervation of the Stomach and Rectum and the Action of Adrenaline in Elasmobranch Fishes" 41: 33: 278: 778: 86: 57: 53: 8: 430: 279: 782: 830: 807: 766: 733: 700: 676: 589: 480: 447: 401: 368: 344: 311: 169: 540: 507: 812: 794: 738: 720: 668: 660: 612: 545: 527: 485: 467: 406: 388: 349: 331: 290: 802: 786: 728: 716: 712: 680: 652: 581: 535: 519: 475: 463: 459: 396: 384: 380: 339: 323: 173: 164: 656: 569: 49: 523: 855: 798: 724: 664: 531: 471: 392: 335: 790: 816: 672: 549: 489: 410: 353: 147: 742: 60:
neuronal flow. The autonomic nervous system is divided primarily into the
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de Groat, William C.; Saum, William R. (January 1972).
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The Central Nervous System: Structure and Functioning
204:Innervations of the parasympathetic nervous system 32:(PNS) groups the nerves into two main groups, the 115:Langley's Classification Tree from his 1921 book 853: 192:Innvervations of the sympathetic nervous system 212: 767:"The sacral autonomic outflow is sympathetic" 698: 316:American Journal of Pharmaceutical Education 312:"Physiology of the Autonomic Nervous System" 122: 72:nervous system, receiving less recognition. 75: 806: 732: 539: 479: 400: 343: 221: 158:Sympathetic and parasympathetic divisions 127: 68:nervous systems with a third system, the 110: 15: 445: 428: 366: 309: 285:. Oxford University Press US. pp.  854: 831:"The Vertebral Column and Spinal Cord" 606: 505: 276: 760: 758: 756: 754: 752: 694: 692: 690: 506:MAEHLE, ANDREAS-HOLGER (2004-04-01). 20:Peripheral nervous system box diagram 638: 636: 634: 632: 630: 628: 567: 563: 561: 559: 501: 499: 424: 422: 420: 310:McCorry, Laurie Kelly (2007-08-15). 272: 270: 225: 136: 26:classification of peripheral nerves 13: 749: 687: 14: 878: 625: 556: 496: 417: 267: 229: 197: 185: 823: 181:Autonomic spinal cord divisions 717:10.1113/jphysiol.1972.sp009708 600: 464:10.1113/jphysiol.1905.sp001128 439: 429:Langley, John Newport (1921). 385:10.1113/jphysiol.1898.sp000726 360: 303: 52:, and can be sub-divided into 1: 446:Langley, J. N. (1905-12-30). 367:Langley, J. N. (1898-07-26). 260: 657:10.1016/j.autneu.2017.04.003 432:The autonomic nervous system 117:The Autonomic Nervous System 7: 611:. W.W. Norton and Company. 213:Classification implications 85:In 1898, British scientist 10: 883: 172:as well as throughout the 80: 862:Peripheral nervous system 705:The Journal of Physiology 568:Lutz, Brenton R. (1931). 524:10.1017/s0025727300000090 452:The Journal of Physiology 373:The Journal of Physiology 123:Classification techniques 38:autonomic nervous systems 30:peripheral nervous system 218:gut and stomach region. 76:Autonomic nervous system 791:10.1126/science.aah5454 607:Cannon, Walter (1932). 867:Medical classification 645:Autonomic Neuroscience 238:This section is empty. 222:Somatic nervous system 128:Traditional techniques 119: 42:central nervous system 21: 114: 44:(CNS) via nerves and 19: 277:Brodal, Per (2004). 87:John Newport Langley 783:2016Sci...354..893E 574:Biological Bulletin 609:Wisdon of the Body 120: 22: 777:(6314): 893–897. 258: 257: 137:Modern techniques 874: 846: 845: 843: 842: 827: 821: 820: 810: 762: 747: 746: 736: 696: 685: 684: 640: 623: 622: 604: 598: 597: 565: 554: 553: 543: 503: 494: 493: 483: 458:(4–5): 374–413. 443: 437: 436: 426: 415: 414: 404: 364: 358: 357: 347: 328:10.5688/aj710478 307: 301: 300: 284: 274: 253: 250: 240:You can help by 233: 226: 201: 189: 50:skeletal muscles 882: 881: 877: 876: 875: 873: 872: 871: 852: 851: 850: 849: 840: 838: 829: 828: 824: 763: 750: 697: 688: 641: 626: 619: 605: 601: 586:10.2307/1537047 566: 557: 512:Medical History 504: 497: 444: 440: 427: 418: 365: 361: 308: 304: 297: 275: 268: 263: 254: 248: 245: 224: 215: 209: 205: 202: 193: 190: 160: 139: 130: 125: 83: 78: 66:parasympathetic 12: 11: 5: 880: 870: 869: 864: 848: 847: 822: 748: 711:(2): 297–314. 686: 624: 617: 599: 555: 518:(2): 153–174. 495: 438: 416: 379:(3): 240–270. 359: 302: 295: 265: 264: 262: 259: 256: 255: 236: 234: 223: 220: 214: 211: 207: 206: 203: 196: 194: 191: 184: 182: 170:thoracic spine 159: 156: 138: 135: 129: 126: 124: 121: 82: 79: 77: 74: 9: 6: 4: 3: 2: 879: 868: 865: 863: 860: 859: 857: 836: 835:www.emory.edu 832: 826: 818: 814: 809: 804: 800: 796: 792: 788: 784: 780: 776: 772: 768: 761: 759: 757: 755: 753: 744: 740: 735: 730: 726: 722: 718: 714: 710: 706: 702: 695: 693: 691: 682: 678: 674: 670: 666: 662: 658: 654: 650: 646: 639: 637: 635: 633: 631: 629: 620: 614: 610: 603: 595: 591: 587: 583: 580:(1): 93–100. 579: 575: 571: 564: 562: 560: 551: 547: 542: 537: 533: 529: 525: 521: 517: 513: 509: 502: 500: 491: 487: 482: 477: 473: 469: 465: 461: 457: 453: 449: 442: 434: 433: 425: 423: 421: 412: 408: 403: 398: 394: 390: 386: 382: 378: 374: 370: 363: 355: 351: 346: 341: 337: 333: 329: 325: 321: 317: 313: 306: 298: 296:0-19-516560-8 292: 288: 283: 282: 273: 271: 266: 252: 249:December 2017 243: 239: 235: 232: 228: 227: 219: 210: 200: 195: 188: 183: 180: 179: 178: 175: 171: 166: 165:thoracolumbar 155: 151: 149: 143: 134: 118: 113: 109: 106: 101: 98: 93: 88: 73: 71: 67: 63: 59: 55: 51: 47: 43: 39: 35: 31: 27: 18: 839:. 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Index


peripheral nervous system
somatic
autonomic nervous systems
central nervous system
ganglia
skeletal muscles
afferent
efferent
sympathetic
parasympathetic
enteric
John Newport Langley

neurogenesis
thoracolumbar
thoracic spine
lumbar spine
Innvervations of the sympathetic nervous system
Innervations of the parasympathetic nervous system

adding to it


The Central Nervous System: Structure and Functioning
369
ISBN
0-19-516560-8
"Physiology of the Autonomic Nervous System"
doi

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