The ganglia of the parasympathetic division of the ans are located in two trunks (or chains), one on each side of the vertebral column, and in a collateral or prevertebral ganglion in two trunks (or chains), one on each side of the vertebral column in a collateral or prevertebral ganglion within the walls of, or close to, the organs served

The ganglia of the parasympathetic division of the ANS are located within the walls of, or close to, the organs they innervate. Parasympathetic ganglia are the autonomic ganglia which belong to the parasympathetic nervous system and it is primarily a homeostatic system promoting. Most are small terminal ganglia that lie near or within the organs they innervate. The exceptions are the four paired parasympathetic ganglia of the head and neck: the ciliary, pterygopalatine, submandibular and otic ganglia.