dorsal root

The dorsal root ganglia contain the cell bodies of afferent nerve fibres (those carrying impulses toward the central nervous system); efferent neurons (carrying motor impulses away from the central nervous system) are present in the ventral root ganglia.

The dorsal root is sensory and the ventral root motor; the first cervical nerve may lack the dorsal root. Oval swellings, the spinal ganglia, characterize the dorsal roots. They are formed of nerve cells that give rise to the sensory nerve fibres. The fibres of the…

…which receives and furnishes one dorsal and one ventral root. On this basis the spinal cord is divided into the following segments: 8 cervical (C), 12 thoracic (T), 5 lumbar (L), 5 sacral (S), and 1 coccygeal (Coc). Spinal nerve roots emerge via intervertebral foramina; lumbar and sacral spinal roots,…

…result from degeneration of the dorsal roots of the spinal cord, giving it its name, which means “dorsal wasting.” The first manifestation is usually “lightning pain,” transient, stabbing pains affecting the legs; this is followed by loss of tendon reflexes and by progressive loss of muscular coordination (ataxia) causing a…