Skip Navigation
Stage 1 / 1 day Stage 2 / 2-3 days Stage 3-1 / 4 days Stage 3-2 / 4-5 days Stage 4 / 6 days Stage 5a-1 / 7 days Stage 5a-2 / 8 days Stage 5b / 9 days Stage 5c / 12 days Stage 6 / 13-17 days Stage 7 / 16-19 days Stage 8 / 23 days Stage 9 / 25 days Stage 10 / 28 days Stage 11 / 29 days Stage 12 / 30 days Stage 13 / 32 days Stage 14 / 33 days Stage 15 / 36 days Stage 16 / 39 days Stage 17 / 41 days Stage 18 / 44 days Stage 19 / 45-47 days Stage 20 / 49 days Stage 21 / 49-52 days Stage 22 / 52-55 days Stage 23 / 56 days
Carnegie Stage   Figure

Junction of epiblast and hypoblast

Junction of epiblast and hypoblast

Low power TEM of a stage 3 embryo in vitro through the epiblast adjacent to the hypoblast (H). 145-170 hours post-insemination (original magnification x10,800). Note lipid droplets (L) and rough endoplasmic reticulum (RER). The RER is very long in the epiblast cells adjacent to the hypoblast generally running along the long axis of the mitochondria or bridging the cytoplasm between adjacent mitochondria. In some cells a cisternum of RER is closely apposed to the parallel membrane of the Golgi complex. In some regions the RER is continuous with annulate lamellae. Lipid globules are common. Some are closely associated with mitochondria.

From: Lopata et al., 1982. Reproduced with permission of the publisher, John Wiley & Sons.


Keywords: Golgi complex, annulate lamellae, cisternum of rough endoplasmic reticulum, cytoplasm, epiblast, hypoblast, junction of epiblast and hypoblast, lipid droplets, rough endoplasmic reticulum


Source: The Virtual Human Embryo.