aortic plexus: a plexus of lymph nodes in the lower portion of the abdominal aorta
structure: a particular complex anatomical part of a living thing
ozone: a colorless gas (O3) soluble in alkalis and cold water; a strong oxidizing agent; can be produced by electric discharge in oxygen or by the action of ultraviolet radiation on oxygen in the stratosphere (where it acts as a screen for ultraviolet radiation)