May require a master's degree and must be a graduate of an accredited physician assistant program. Must meet any state requirements pertaining to a physician assistant. Familiar with standard concepts, practices, and procedures within a particular field. Relies on experience and judgment to plan and accomplish goals.
home / medterms medical dictionary a-z list / ephedra definition Medical Definition of Ephedra Ephedra: A medicinal herb, known scientifically as Ephedra sinica and Ephedra equisetina, also known as mahuang and herbal ecstasy. Ephedra comes from the dried rhizome and root of the plant. The main active ingredients in ephedra are ephedrine and pseudoephedrine which account for the medicinal properties of the herb. Both ephedrine and pseudoephedrine are central nervous system stimulants that act as decongestants but, in high doses, can raise the blood pressure.
Photosynthesis (the conversion of carbon dioxode to sugars using the sunâs energy) usually takes place in the leaves but in switch-plants this is undertaken in the green stems. Ephedra produce small, cone-like reproductive structures followed by berry-like fruits, which are usually bright red or orange in colour. An ususual coloured form can be found in the collection, Ephedra americana var. andina, from Chile which bears white rather than the normal red berries.