extraembryonic mesoderm

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Related to extraembryonic mesoderm: chorion, extraembryonic membranes

ex·tra·em·bry·on·ic mes·o·derm

extraembryonic cells that, although derived from the zygote, are not part of the embryo proper and contribute to the fetal membranes (for example, amnion).
Synonym(s): primary mesoderm

extraembryonic mesoderm

Etymology: L, extra, outside; Gk, en + bryein, to grow, mesos, middle, derma, skin
any mesoderm in the uterus that is not involved with the embryo itself. Included are mesoderms in the amnion, chorion, yolk sac, and connecting stalk.

extraembryonic mesoderm

Mesoderm lying outside the embryo proper and involved in the formation of amnion, chorion, yolk sac, and body stalk.
See also: mesoderm


the middle of the three primary germ layers of the embryo, lying between the ectoderm and entoderm; from it are derived the connective tissue, bone, cartilage, muscle, blood and blood vessels, lymphatics, lymphoid organs, notochord, pleura, pericardium, peritoneum, kidneys and gonads.

extraembryonic mesoderm
located outside the developing embryo and forming its accessory organs.
paraxial mesoderm
adjacent to the mid line beneath the epiblast of the embryo which develop into somites.
somatic mesoderm
the outer layer of the developing mesoderm.
splanchnic mesoderm
the inner layer of the developing mesoderm.