Reproduction : The Placenta As An Endcrine Gland

The placenta is also ___, initially producing an additional ___ known as ___ ( ___ ).

___ appears in the ___ from about ___ after ___; ____ antibodies are used to detect its presence in urine in pregnancy-testing kits.

HCG is initially secreted by the cells of the ___, but later it comes entirely form the ___ and its role is to maintain the ___ as ___ ( secreting ___ & ___ ) for the first __ weeks of pregnancy.

When the ___ eventually breaks down the ___ itself secretes ___ as without the maintenance of hormone levels, conditions favourable to a ___ are not maintained in the ___ and a ___ results.