Understanding the 5 Divisions of Spinal Nerves: A Comprehensive Guide

31 pairs of spinal nerves exit the vertebral column, grouped by region:

1. Cervical (8 pairs, C1–C8): Neck, shoulder, arm, hand, diaphragm (C3–5). C1–C7 exit above pedicle; C8 exits below C7.
2. Thoracic (12 pairs, T1–T12): Intercostal muscles, abdominal wall, trunk sensation.
3. Lumbar (5 pairs, L1–L5): Lower back, hip flexors, knee extensors, foot dorsiflexors.
4. Sacral (5 pairs, S1–S5): Plantar flexion, bowel/bladder, perineum, sciatic nerve (L4–S3).
5. Coccygeal (1 pair, Co1): Coccygeal region sensation.

Each nerve: dorsal root (sensory) + ventral root (motor) → mixed nerve. Dermatomes/myotomes guide lesion localization.