Stage 3 embryo in vitro showing the polar, or anterior-posterior (A-P), and the perpendicular, or dorsal-ventral (D-V), axes. The blastocyst has expanded. The inner cell mass (ICM) is at the embryonic pole (EP). The opposite side of the blastocyst is the abembryonic pole (AP).
From: Veeck and Zaninovic´, 2003. Reproduced with permission of the publisher, Francis and Taylor Group.
Keywords: abembryonic pole, axes of the blastocyst, blastocyst(s), embryonic pole, inner cell mass (embryoblast)
Source: The Virtual Human Embryo.