Peri

PERI (peri), a Greek prefix relating to anatomical formations and pathological processes located in immediate proximity to a particular object of primary anatomical significance (pericardium, perimetrium, perichondritis, etc.). Usually this prefix refers to the outer covering of the corresponding organ, for example, its serous covering, the fibrous capsule of the organ, the coverings of individual histological elements (perimysium, perineurium), etc. Sometimes in relation to the outer covering of a vessel, instead of adventitia, the term perithelium is used. The prefix P. is thus given to anatomical formations that are organically connected with the substance of the organ as a whole. On the other hand, this prefix emphasizes a certain independence of the same formations, for example, in histological, embryogenetic, pathogenetic, etc. relations: perimetrium, pericardium, etc. may exhibit certain pathological phenomena without this being organically connected with the uterus, heart, etc. From this same point of view, the existence of such diseases as perivisceritis (polyserositis) can be understood.