Stage 3 embryo in vitro that is partially hatched (day 7). A large part of the zona pellucida is open at the hatching site near the inner cell mass (embryoblast).
From: Veeck and Zaninovic´, 2003. Reproduced with permission of the publisher, Francis and Taylor Group.
Keywords: blastocystic cavity (blastocoele), hatching site, inner cell mass (embryoblast), mural trophoblast, partially hatched embryo, zona pellucida
Source: The Virtual Human Embryo.