Each nerve pair exits the spinal column through a bony opening called the intervertebral foramen , located just below its corresponding vertebra (e.g., the T4 nerve exits below the T4 vertebra).
| Nerve | Lesion / Irritation | Clinical Finding | |-------|--------------------|------------------| | Any intercostal | Herpes zoster (shingles) | Vesicular rash in a single dermatome (e.g., T4–T6 most common) | | T2–T3 | Lung cancer (Pancoast tumor) | Pain down medial arm (T2) + Horner’s syndrome (sympathetic chain) | | T7–T11 | Post-thoracotomy pain | Numbness or neuralgia along thoracoabdominal nerves | | T10 | Abdominal surgery | Loss of sensation at umbilicus; reflex (contraction on stroking) lost | | T12 | Subcostal nerve entrapment | Pain in lower quadrant (mimics appendicitis) | thoracic nerve diagram
The are the 12 pairs of nerves emerging from the thoracic segments of the spinal cord (T1 to T12). Unlike cervical and lumbosacral nerves, they do not form complex plexuses (except T1 and T2 contributions to the brachial plexus). Instead, they retain a relatively segmental, metameric organization , making them ideal for understanding dermatomes and myotomes. Each nerve pair exits the spinal column through
The thoracic nerves are unique because, unlike the cervical or lumbar nerves which form complex "plexuses" (interweaving networks), most thoracic nerves run directly to the parts of the body they innervate. they retain a relatively segmental
The thoracic nerves play a crucial role in controlling various bodily functions, such as:
Here's a simplified diagram of the thoracic nerves: