embryonic disc
nounUK /ˌembriˈɒnɪk dɪsk/
US /ˌembriˈɑːnɪk dɪsk/
A tiny flat group of cells that grows into a baby animal or human.
The embryonic disc forms very early in pregnancy.
RELATED WORDS
OTHER MEANINGS
2. The flat plate of cells in a bird's egg from which the chick develops.
In a fertilized chicken egg, the embryonic disc sits on top of the yolk.
3. The two-layered structure in early mammalian development that gives rise to all body tissues.
The embryonic disc splits into the epiblast and hypoblast layers.
4. A stage in early development before the embryo takes on a clear shape.
Scientists studied the embryonic disc to understand how organs first form.