Nerve root anatomy & nerve root pain

Nerve root anatomy and the mechanisms behind radicular pain are the main focus here. The explanation reviews the thecal sac, nerve root sleeves, dorsal root ganglion, cauda equina, and the intervertebral foramen, showing where nerve roots travel and why some structures, especially the dorsal root ganglion, can make symptoms more severe when irritated. A key distinction is made between radicular pain and radiculopathy: pain comes from abnormal afferent firing, while radiculopathy involves impaired signal conduction causing sensory loss or weakness. The teaching then breaks pain mechanisms into two linked categories: mechanical pressure and chemical irritation. Mechanical compression can reduce venous outflow, create edema, deprive the nerve of oxygen, and damage myelin, leading to abnormal impulse-generating sites. Chemical irritation, often from disc material, can also inflame and disrupt the nerve, causing similar abnormal firing. The summary also covers why small amounts of pressure may be enough to provoke symptoms, why imaging findings do not always match pain severity, and how inflammation can spread to the dorsal root ganglion and spinal cord, helping explain symptoms that extend beyond classic dermatomal patterns.