Week 17 Anatomy


Property Cervical Thoracic Lumbar
Vertebral body Small, oval. Heart shaped, Medium Big, kidney shaped
Spinous process Bifid and obliquely angled down Long and slope down Short and horizontal
Facet joints 45 degrees  angles inferiorly anteriorly Angled coronally Angled sagitally
Movement Flexion, extension, lateral flexion, rotation Rotation Flexion, extension, lateral flexion
Special Transverse foramina Costal articulation on transverse process and body Short thick, hatchet like
Vertebral foramen Large, triangular Circular and smaller Triangular, medium size


Vertebral column:

  • Cervical 7
  • Thoracic 12
  • Lumbar 5
  • sacral 5
  • coccyx


Atypical vertebrae:

  • C1(atlas)
  • C2(axis, odontoid process)
  • C7(long spinous process, not bifid)


General characteristics of vertebrae.

  • Vertebral body
  • Transverse process
  • Spinous process
  • Pedicle
  • Lamina
  • Facet joint/zygoapophysial joint
  • Vertebral canal
  • Inferior and superior vertebral notch.





Spinal cord:


Conscious tracts – Comprised of the dorsal column-medial lemniscal pathway, and the anterolateral system.

  • Dorsal column – vibration, proprioception, fine touch. Dorsal column–> medial leminiscus(brain stem). UL travel in fasciculus cuneatus. LL travel in fasciculus gracillis. Decuss in medulla as second order neuron which goes to thalamus(ventral posterolateral nucleus). Third order neuron: Thalamus–> internal capsule–> sensory cortex.
  • Anterolateral spinothalamic tract – crude touch, pressure.
  • Lateral spinothalamic tract  – pain, temperature
    Both enter and ascend 1-2levels then terminate in dorsal horn(substantia gelatinosa). 2nd order decusses, separate into the two tracts and rises to thalamus(ventral posterolateral nucleus) Then third neuron–> internal capsule to sensory cortex.

Unconscious tracts – Comprises of the spinocerebellar tracts. – balance


Descending tracts

  • Cortex –> internal capsule(between thalamus and basal ganglia)–> crus of cerebri–> midbrain/pons/medulla–> divides into lateral and anterior corticospinal tracts–> terminate in ventral horn at synapse with lower motor neuron.
  • Lateral tract decuss at medulla while anterior spinal tract descends to cervical/thoracic level then decuss.

Blood supply / venous drainage of spine.

  • 1 anterior spinous artery and 2 posterior spinous artery
  • At each level the dorsal rami gives segmental(posterior intercostal) artery which is important
  • Epidural plexus with 2 anterior and posterior longitudinal sinuses. Anterior external venous plexus. Lumbar Vein.
  • 3 anterior and posterior spinal veins.








C1 & C2 plus ligaments and movements

  • 3 atlanto axial joints – 2 lateral and odontoid in middle
  • Joint capsules and tectorial membrane.
  • Rotation.



  • Cruciate ligament on odontoid – superior/inferior longitudinal band, transverse ligament of atlas(on C1)
  • Alar ligament
  • Tectorial membrane(continuation of posterior longitudinal ligament)


Patterns of spinal injury (popular question)

  • Complete transection. (Wikipedia)
    • Cervical
      • Cervical (neck) injuries usually result in full or partial tetraplegia (Quadriplegia).
      • Injuries at the C-1/C-2 levels will often result in loss of breathing, necessitating mechanical ventilators or phrenic nerve pacing.
      • Injuries at C3 and above typically result in loss of diaphragm function, necessitating the use of a ventilator for breathing.
      • C4 results in significant loss of function at the biceps and shoulders.
      • C5 results in potential loss of function at the biceps and shoulders, and complete loss of function at the wrists and hands.
      • C6 results in limited wrist control, and complete loss of hand function.
      • C7 and T1 results in lack of dexterity in the hands and fingers, but allows for limited use of arms.
      • Patients with complete injuries above C7 typically cannot handle activities of daily living making functioning independently difficult and not often possible.
      • Additional signs and symptoms of cervical injuries include:
        • Inability or reduced ability to regulate heart rate, blood pressure, sweating and hence body temperature.
        • Autonomic dysreflexia or abnormal increases in blood pressure, sweating, and other autonomic responses to pain or sensory disturbances.
    • Thoracic
      • Complete injuries at or below the thoracic spinal levels result in paraplegia. Functions of the hands, arms, neck, and breathing are usually not affected.
      • T1 to T8 : Results in the inability to control the abdominal muscles. Accordingly, trunk stability is affected. The lower the level of injury, the less severe the effects.
      • T9 to T12 : Results in partial loss of trunk and abdominal muscle control.
      • Typically lesions above the T6 spinal cord level can result in autonomic dysreflexia.
    • Lumbosacral
      • The effects of injuries to the lumbar or sacral regions of the spinal cord are decreased control of the legs and hips, urinary system, and anus.


  • Hemisection (Brown-Séquard’s syndrome)
    • Interruption of the lateral corticospinal tracts:
      • Ipsilateral spastic paralysis below the level of the lesion
      • Babinski sign ipsilateral to lesion
    • Interruption of posterior white column:
      • Ipsilateral loss of tactile discrimination, vibratory, and position sensation below the level of the lesion
    • Interruption of lateral spinothalamic tracts:
      • Contralateral loss of pain and temperature sensation.
      • This usually occurs 2-3 segments below the level of the lesion.
  • Central cord syndrome.
    • UL motor affected more than lower limb,  variable sensory loss below and bladder symptoms such as urinary retention.
  • Anterior spinal artery syndrome.
    • Motor weakness bilaterally
    • Loss of pain and temp sensation bilaterally
    • Maintain proprioception, vibration and fine touch.


Intervertebral discs / ligaments.

  • Supraspinous ligament
  • Interspinous ligament
  • Ligamentum flavum(between lamina)
  • Posterior longitudinal ligament(back of v body)
  • Ant longitudinal ligament (ant to vertebral body)
  • Nuchal ligament – between occiput and C7 supraspinous ligament.