Sympathetic Trunk Formed by paravertebral ganglia interganglionic branches ◆ Lie on either side of vertebral column from base of skull to coccyx The trunks of two side unite in front of the coccyx at a small swelling, the ganglion Impar Sympathetic trunk in thorax14 Sympathetic Trunk Formed by paravertebral ganglia & interganglionic branches Lie on either side of vertebral column from base of skull to coccyx The trunks of two side unite in front of the coccyx at a small swelling, the ganglion impar Sympathetic trunk in thorax