Thoracic Nerve Distribution __full__ -

The intercostal nerves can be further divided into three main branches:

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

The ventral rami of the thoracic nerves are also known as the intercostal nerves. These nerves run between the ribs, hence the name "intercostal." They are responsible for innervating the muscles of the thoracic wall, including the intercostal muscles, and providing sensation to the skin of the thoracic region. The thoracic nerves are distributed throughout the thoracic

The thoracic nerves are distributed throughout the thoracic region, including:

| Landmark | Corresponding Thoracic Nerve | | :--- | :--- | | Supraclavicular fossa | C3–C4 (not thoracic) | | Apex of axilla | T1–T2 | | Sternal angle (manubriosternal) | T2 | | Nipple (4th intercostal space) | | | Xiphoid process | T6 | | Costal margin | T7 | | Umbilicus | T10 | | Pubic symphysis / inguinal ligament | T12 / L1 |

Supplies the deep muscles of the back and provides sensation to the skin of the back. Ventral (Anterior) Ramus: T11cap T 11