Chorionic allantoic

Evaluate the yolk sac, the ectoplacental cone, and the chorionic-allantoic membrane, and their morphological integrity. 

The integrity of the ectoplacental cone and chorionic-allantoic membrane are considered when assigning the yolk sac score. The ectoplacental cone should be attached to the base of the... 

A similar approach is considered when evaluating the chorionic-allantoic membrane. The chorion should be fused to the allantois and should appear semi-translucent (allantois) and half-opaque/vascularized (chorion). Examples of abnormalities of this structure include separation between the chorionic and allantoic membranes, reduction in size, or blood pooled within the structure. 

Chorion—Pooled blood Chorion-allantoic membrane separated... 

Chorionic gonadotropin injected into pregnant rabbits is selectively stored in their placentae, but is not excreted into the urine or the amniotic or allantoic fluids. Human placenta stores and adsorbs chorionic gonadotropin. 

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