The sympathetic nuclei are clusters of neuronal cell bodies located in the central nervous system, specifically within the intermediolateral cell column (IML) of the spinal cord.

• Found in the lateral horn of the spinal cord gray matter
• Present from T1 to L2/L3 spinal cord segments
• Also referred to as the thoracolumbar outflow

• Contain preganglionic sympathetic neurons
• Axons exit via ventral roots, then enter the sympathetic chain ganglia (paravertebral) or prevertebral ganglia
• Postganglionic neurons project to target organs:
  • Heart (↑ rate and contractility)
  • Pupils (dilation)
  • Skin (sweating, vasoconstriction)
  • Gastrointestinal tract (↓ motility)

• Horner Syndrome: Damage to the sympathetic pathway causes ptosis, miosis, and anhidrosis
• Spinal cord injuries above T1 can interrupt sympathetic output
• Autonomic dysreflexia in spinal lesions above T6

• sympathetic_nervous_system
• autonomic_nervous_system