Spinal cord
 The spinal cord provides a crucial information  conduit, connecting the brain with most of  the body. It is the target ...
 Failure to diagnose some disorders of the  spinal cord, such as spinal cord compression,  can be catastrophic and may re...
 The sensory component of each spinal nerve  is distributed to a dermatome, a well-defined  segmental portion of the skin...
 dermatomes for C5, C6, C7, C8, and T1 are  confined to the arm C4 and T2 dermatomes are contiguous over  the anterior t...
 Nipple-T4 Umbilicus – T 10
 The territories of dermatomes tend to  overlap, making it difficult to determine the  absence of a single segmental inne...
Myotomes myotome refers to the skeletal musculature  innervated by motor axons in a given spinal  root Most muscles are ...
Segment-Pointer Muscles.Root            Muscle C5             Deltoid C5             Biceps C6             Brachiora...
Rexed’s laminae
Rexeds laminae Lamina I This thin marginal layer contains neurons that  respond to noxious stimuli [pain,  temperature] ...
 Lamina II- substantia gelatinosa made up of small neurons, some of which  respond to noxious stimuli. Substance P, a n...
 Laminas III and IV  [nucleus proprius]Their main input is from fibers that convey  position and light touch sense. Lami...
 Lamina VI deepest layer ,contains neurons that respond  to mechanical signals from joints and skin.
Lamina VII contains the cells of the dorsal nucleus  (Clarkes column) medially as well as a large  portion of the ventral...
 also contains the intermediolateral nucleus  (or intermediolateral cell column) in thoracic  and upper lumbar regions. ...
Laminas VIII and IX represent motor neuron groups in the medial  and lateral portions of the ventral gray  column The me...
 The lateral motor neuron column contains  LMNs for the distal muscles of the arm and  leg flexor muscles are innervated...
Lamina X represents the small neurons around the  central canal or its remnants.
White Matter composed of myelinated and unmyelinated  nerve fibers. The fast-conducting myelinated fibers form  bundles ...
 The lateral and ventral white columns contain  tracts that are not well delimited and may  overlap in their cross sectio...
Location of tracts
Descending tracts in the SpinalCord. Lateral corticospinal    Fine motor function  (pyramidal) tract        (controls di...
 Anterior                 Gross and postural  corticospinal tract       motor function                            (proxi...
 Rubrospinal       Motor function Reticulospinal    Modulation of                    sensory                    transm...
 Descending             Modulation of  autonomic               autonomic                          functions Tectospinal...
Ascending tracts Dorsal column     Fine touch, system              proprioception,                     two-point        ...
 Dorsal spinocerebellar     Movement and  tract                       position mechanisms Ventral spinocerebellar    M...
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
Spinal cord by DR.ARSHAD
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Spinal cord by DR.ARSHAD

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Spinal cord by DR.ARSHAD

  1. 1. Spinal cord
  2. 2.  The spinal cord provides a crucial information conduit, connecting the brain with most of the body. It is the target of a number of disease processes, some of which (eg, spinal cord compression) are treatable but rapidly progressive if not treated.
  3. 3.  Failure to diagnose some disorders of the spinal cord, such as spinal cord compression, can be catastrophic and may relegate the patient to a lifetime of paralysis. A knowledge of the architecture of the spinal cord and its coverings, and of the fiber tracts and cell groups that comprise it, is essential.
  4. 4.  The sensory component of each spinal nerve is distributed to a dermatome, a well-defined segmental portion of the skin in many patients there is no C1 dorsal root, there is no C1 dermatome when a C1 dermatome does exist as an anatomic variant, it covers a small area in the central part of the neck, close to the occiput
  5. 5.  dermatomes for C5, C6, C7, C8, and T1 are confined to the arm C4 and T2 dermatomes are contiguous over the anterior trunk. thumb, middle finger, and fifth digit are within the C6, C7, and C8 dermatomes, respectively
  6. 6.  Nipple-T4 Umbilicus – T 10
  7. 7.  The territories of dermatomes tend to overlap, making it difficult to determine the absence of a single segmental innervation on the basis of sensory testing
  8. 8. Myotomes myotome refers to the skeletal musculature innervated by motor axons in a given spinal root Most muscles are innervated by motor axons that arise from several adjacent spinal roots. Nevertheless, lesions of a single spinal root, in many cases, can cause weakness and atrophy of a muscle
  9. 9. Segment-Pointer Muscles.Root Muscle C5  Deltoid C5  Biceps C6  Brachioradialis C7  Triceps  Quadriceps femoris L3, L4  Extensor hallucis L5 longus S1  Gastrocnemius
  10. 10. Rexed’s laminae
  11. 11. Rexeds laminae Lamina I This thin marginal layer contains neurons that respond to noxious stimuli [pain, temperature] and send axons to the contralateral spinothalamic tract.
  12. 12.  Lamina II- substantia gelatinosa made up of small neurons, some of which respond to noxious stimuli. Substance P, a neuropeptide involved in pathways mediating sensibility to pain, is found in high concentrations in laminas I and II.
  13. 13.  Laminas III and IV [nucleus proprius]Their main input is from fibers that convey position and light touch sense. Lamina Vcontains cells that respond to both noxious and visceral afferent stimuli.
  14. 14.  Lamina VI deepest layer ,contains neurons that respond to mechanical signals from joints and skin.
  15. 15. Lamina VII contains the cells of the dorsal nucleus (Clarkes column) medially as well as a large portion of the ventral gray column. Clarkes column contains cells that give rise to the posterior spinocerebellar tract.
  16. 16.  also contains the intermediolateral nucleus (or intermediolateral cell column) in thoracic and upper lumbar regions. Preganglionic sympathetic fibers project from cells in this nucleus, via the ventral roots and white rami communicantes, to sympathetic ganglia.
  17. 17. Laminas VIII and IX represent motor neuron groups in the medial and lateral portions of the ventral gray column The medial portion (also termed the medial motor neuron column) contains the LMNs that innervate axial musculature
  18. 18.  The lateral motor neuron column contains LMNs for the distal muscles of the arm and leg flexor muscles are innervated by motor neurons located close to the central canal extensor muscles are innervated by motor neurons located more peripherally
  19. 19. Lamina X represents the small neurons around the central canal or its remnants.
  20. 20. White Matter composed of myelinated and unmyelinated nerve fibers. The fast-conducting myelinated fibers form bundles (fasciculi) that ascend or descend for varying distances Fiber bundles with a common function are called tracts
  21. 21.  The lateral and ventral white columns contain tracts that are not well delimited and may overlap in their cross sectional areas the dorsal column tracts are sharply defined by glial septa
  22. 22. Location of tracts
  23. 23. Descending tracts in the SpinalCord. Lateral corticospinal  Fine motor function (pyramidal) tract (controls distal musculature) Modulation of sensory functions
  24. 24.  Anterior  Gross and postural corticospinal tract motor function (proximal and axial musculature Vestibulospinal tract  Postural reflexes
  25. 25.  Rubrospinal  Motor function Reticulospinal  Modulation of sensory transmission (especially pain) Modulation of spinal reflexes
  26. 26.  Descending  Modulation of autonomic autonomic functions Tectospinal  Reflex head turning Medial longitudinal  Coordination of fasciculus head and eye movements
  27. 27. Ascending tracts Dorsal column  Fine touch, system proprioception, two-point discrimination Spinothalamic tracts  Sharp pain, temperature, crude touch
  28. 28.  Dorsal spinocerebellar  Movement and tract position mechanisms Ventral spinocerebellar  Movement and position mechanisms

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