Amnion

(am’ ’-ne-on) [a/jvior, a young lamb] The innermost of the fetal membranes; it i continuous with the fetal epidermis at the um bilicus, forming a complete sheath for the umbilical cord and a sac or bag in which the fetus is enclosed. It contains one or two pints of liquor amnii. It is a double, non vascular membrane, the inner layer or sac derived from the epiblast, the outer from the mesoblast. The cavity of the inner folds is called the true amnion, that cf the outer, the false. A., Dropsy of, exce ive secretion of liquor amnii. 50