Throughout the extent of the sympathetic trunks, small raised areas are visible. These collections of neuronal cell bodies outside the CNS are the paravertebral sympathetic ganglia. There are usually: three ganglia in the cervical region, eleven or twelve ganglia in the thoracic region, four ganglia in the lumbar region, four or five ganglia in the sacral region, and the ganglion impar anterior to the coccyx (Fig. 4.135).