#summary Spinal Cord
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This page is intended to discover component structure of spinal cord of biological human, sitting in between mind and peripheral organs.

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= SPINAL CORD STRUCTURE =

== BASIC INFORMATIOIN ==

  * regions - cervical (C1-C8), thoracic (T1-T12), lumbar (L1-L5), sacral (S1-S5), coccygeal (CX = CX1-CX3)
  * width - 1 cm (thoracic/sacral) /2 cm (cervical-lumbar)
  * height - 45 cm (men)/43 cm (women)

http://www.dartmouth.edu/~humananatomy/figures/chapter_3/3-2_files/image002.jpg

  * dorsal horn and afferent connections:

<img src="http://www.intechopen.com/source/html/43833/media/image2.jpeg" height=400>
  
  * receptors classification: proprioceptors, nociceptors, mechanoreceptors

http://www.nature.com/nrn/journal/v4/n4/images/nrn1073-f1.jpg

  * spinal cord cross section - ascending and descending tracts

http://upload.wikimedia.org/wikipedia/commons/thumb/b/b2/Spinal_cord_tracts_-_English.svg/800px-Spinal_cord_tracts_-_English.svg.png

  * motor interneurons:

http://www.ib.cnea.gov.ar/~redneu/2013/BOOKS/Principles%20of%20Neural%20Science%20-%20Kandel/gateway.ut.ovid.com/fulltextservice/ct%7B06b9ee1beed594190674f1983457a7dd32af6a0d5a4c9892~43/da6c36ff5.gif.png

  * *interneurons of indirect supraspinal connections*: primary pathway for alpha-motoneurons
  * *renshaw interneurons*: interneurons of direct monosynaptic connections with alpha-motoneurons, some fibers of CST/LVST/RST, negative feedback on the same alpha-neurons; stop firing to be ready for next supraspinal signal
  * integrated rhythmic movements of upper and lower extremities like walking and running
   * *intersegmental interneurons*: reciprocal inhibition (excite agonist muscles/ inhibit antagonist muscles), feedback inhibition (selectively inhibit LMN to proper pattern in agonist muscle group)
   * *commissural interneurons*: to contralateral neurons (crossed extensor reflexes, alternate rhythms of both upper and lower extremities during running and walking)

== SPINAL CORD LAMINAE AND LEVELS - REFERENCE ==

http://www.cixip.com/Public/kindeditor/attached/image/20121026/20121026103953_22628.jpg

== SPINAL CORD LAMINAE AND LEVELS ==
(generated)

<img src="http://thebrain.mcgill.ca/flash/a/a_03/a_03_cl/a_03_cl_dou/a_03_cl_dou_1d.jpg" alt="unavailable" style="max-width: 100%;">

|| *Level/Lamina* || *LO* || *LI* || *LII* || *LIII-IV* || *LV-VI* || *LVIIS* || *LVIIM* || *LVIII* || *LIX* || *LX* ||
|| C1 || LCN || MG || SG || NPR || ACN || CCN || || VMN || SAN || ||
|| C2 || LCN || MG || SG || NPR || ACN || CCN || || VMN || SAN || ||
|| C3 || LCN || MG || SG || NPR || ACN || CCN || || VMN || SAN,PHN || ||
|| C4 || LCN || MG || SG || NPR || ACN || CCN || || VMN || SAN,PHN,PLN,VLN || ||
|| C5 || LCN || MG || SG || NPR || ACN || CBN || || VMN || SAN,PHN,PLN,VLN || ||
|| C6 || LCN || MG || SG || NPR || ACN || CBN || || VMN || SAN,PLN,VLN || ||
|| C7 || LCN || MG || SG || NPR || ACN || CBN || || VMN || PLN,VLN || ||
|| C8 || LCN || MG || SG || NPR || CLN || CBN || RPL || VMN || PLN,VLN || ||
|| T1 || LSN || MG || SG || NPR || CLN || IMM || RPL,IML,CSC || VMN || PMN || ||
|| T2 || LSN || MG || SG || NPR || CLN || IMM || IML,CSC || VMN || PMN || ||
|| T3 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T4 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T5 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T6 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T7 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T8 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T9 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T10 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T11 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| T12 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || ||
|| L1 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN || DCN ||
|| L2 || LSN || MG || SG || NPR || CLN || IMM || IML || VMN || PMN,PLN,VLN || DCN ||
|| L3 || || MG || SG || NPR || CLN || || || VMN || PLN,VLN || ||
|| L4 || || MG || SG || NPR || || || || VMN || PLN,VLN || ||
|| L5 || || MG || SG || NPR || || || || VMN || PLN,VLN || ||
|| S1 || || MG || SG || NPR || || || RPL,SPS || VMN || PLN,VLN,ONN || DCN ||
|| S2 || || MG || SG || NPR || || || RPL,SPS || VMN || ONN || DCN ||
|| S3 || || MG || SG || NPR || || || RPL,SPS || VMN || ONN || DCN ||
|| S4 || || MG || SG || NPR || || || || VMN || || DCN ||
|| S5 || || MG || SG || NPR || || || || VMN || || ||
|| CX || || MG || SG || NPR || || || || VMN || || ||

== SUBCORTICAL SENSORY SYSTEMS ==

  * subcortical visual system
  * somatosensory system
  * subcortical auditory system
  * gustatory system
  * viscerosensory system
  * humerosensory system

= SPINAL CORD CONNECTIVITY =

  * see [SpinalCordTracts Spinal Cord Tract Details]

= FUNCTIONAL GROUPS =

  * *spinothalamocorticospinal cycle*: 
   * somatic body mechanical sensory -> {medial lemniscus system} -> VPL -> SI -> MI -> {lateral corticospinal tract} -> flexors (conscious motor)
   * somatic head mechanical sensory -> {anterior trigeminothalamic tract} -> VPM -> SI (perception)
   * somatic body pain sensory -> {paleospinothalamic system} -> VPI -> INS (conscious motivation)
   * somatic head pain sensory -> {dorsal trigeminal tract} -> VPI -> INS (conscious motivation)
   * PMC -> {lateral corticospinal tract} -> extensors (conscious motor)
  * *spinohypothalamospinal cycle*: visceral pain -> LSN -> {spinohypothalamic tract} -> hypothalamus -> {hypothalamospinal tract} -> sympathetic/parasympathetic
  * *spinomesencephalospinal cycle*: 
   * somatic pain -> MG -> {spinomesencephalic tract} -> PAG -> Gigantocellular Reticular Nucleus -> {medullary reticulospinal tract} -> extensors (reflexive)
   * visceral pain -> IMM -> {spinomedulloreticular tract} -> Gigantocellular Reticular Nucleus
  * *spinosolitariospinal cycle*: visceral pain -> LSN -> {spinosolitary tract} -> SOL -> Parabrachial Nucleus -> SOL -> {solitariospinal system} -> diaphragm
  * *spinoponcoreticulocorticospinal cycle*: visceral pain -> IMM -> Medial Pontine Reticular Formation -> VA -> PMC -> {pontine reticulospinal tract} -> extensors
  * *spinotectospinal*: visceral mechanical -> NPR -> {spinotectal tract} -> Superior Colliculus -> {tectospinal tract} -> oculomotor
  * *spinocerebellorubrospinal cycle*: 
   * mechanical sensory -> {direct spinocerebellar system} -> CR -> RDN -> {corticobulbospinal system} -> flexors (automatic)
   * mechanical sensory -> Inferior Olivary Nucleus -> {spinoolivary tract} -> CR
  * *spinovestibulospinal cycle*:
   * cutaneous sensory -> CCN -> {spinovestibular tract} -> VBN
   * VBN -> {medial vestibulospinal tract} -> upper motor extensors
   * VBN -> {lateral vestibulospinal tract} -> lower motor extensors