pentylenetetrazol: a drug used as a circulatory and respiratory stimulant; larger doses cause convulsions in shock therapy; Metrazol is a trademark
medicine: (medicine) something that treats or prevents or alleviates the symptoms of disease
calyx: (botany) the whorl of sepals of a flower collectively forming the outer floral envelope or layer of the perianth enclosing and supporting the developing bud; usually green