n. the wall of the embryonic gut, which consists of a layer of endoderm with a layer of mesoderm outside it. The yolk sac is a continuation of this structure. Compare somatopleure.
n. the body wall of the early embryo, which consists of a simple layer of ectoderm lined with mesoderm. The amnion is a continuation of this structure outside the embryo. Compare splanchnopleure.... somatopleure
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