See Also: primitive streak(medicine)
Herbal medicine (botanical medicine, herbology, phytomedicine)(health)
streak(1)(dictionary)
streak(encyclopedia)
streak(dictionary)
streak(2)(dictionary)
Hot Streak - Poker(gambling)
fatty streak(medicine)
streak 1, noun(dictionary)
streak 2, verb(dictionary)

primitive streak (medicine)


primitive streak


An ectodermal ridge in the midline at the caudal end of the embryonic disk from which arises the intraembryonic mesoderm; achieved by inward and then lateral migration of cells; in human embryos, it appears on day 15 and gives a cephalocaudal axis to the developing embryo.

Synonym: germinal streak.