Thoracic Nerve Distribution Jun 2026

The 12 pairs of thoracic nerves are classified based on the vertebrae they exit below. Each nerve splits into two primary branches:

) that emerge from the thoracic segments of the spinal cord. Unlike cervical or lumbar nerves, thoracic nerves generally do not form complex plexuses (except for thoracic nerve distribution

| Nerve | Region | Key Motor Targets | Key Sensory (Dermatome) | | :--- | :--- | :--- | :--- | | | Superior thorax | Intercostals, hand muscles (via T1 contribution to brachial plexus) | Medial forearm/axilla | | T2 | 1st-2nd intercostal space | Intercostals | Upper chest, axilla (intercostobrachial nerve) | | T3-T6 | Upper thorax | External/internal intercostals | Anterior chest wall (nipple = T4) | | T7-T9 | Mid-lower thorax | Intercostals, serratus posterior inferior | Epigastrium (xiphoid = T6) | | T10 | Subcostal region | Abdominal obliques, transversus abdominis | Umbilicus (landmark) | | T11-T12 | Lower thorax/flank | Abdominal muscles, quadratus lumborum | Hypogastrium, inguinal region | The 12 pairs of thoracic nerves are classified

Thoracic Spine: What It Is, Function & Anatomy - Cleveland Clinic quadratus lumborum | Hypogastrium

After exiting the intervertebral foramen, each thoracic nerve divides into two primary branches: