等幅骨虫纲：肉足亚门辐足总纲海洋原生动物中的一个纲，常为浮游生物，其特征为有由硫酸锶构成的骨骼即辐射刺(一般为半幅刺20条，或全幅刺10条，大致在细胞中心相连)，细胞外皮(胶泡)以及内包被(被膜)(常紧贴在细胞中心团块内壁)等结构。包括以下5目：全射棘虫目(Holacanthida)，粘合棘目(Symphyacanthida)，松棘虫目(Chaunacanthida)，节棘虫目(Arthracanthida)和光芒虫目(Actineliida)- petrousitis
- Petruschky's litmus whey, spinalgia
- Petzetaki's test(reaction)
- Peucetia
- pexia
- pexic
- pexin
- pexinogen
- pexis
- -pexy
- Peyer's patches(glands, insulae, plaques)
- peyote
- peyotl
- Peyronie's disease
- Peyrot's thorax
- Pfannenstiel's incision
- Pfeifferella
- Pfeiffer's bacillus,law, phenomenon(reac-tion)
- Pfeiffer's disease, glandular fever
- p-fluorophenylalanine
- Pflüger's cords,law,tubes
- Pfuhl's sign
- pg.
- P.G.
- PG