Karen, I loved the sink analogy to tell mothers. It is not
physiological, but it clearly makes the point! My somewhat
physiological analogy is that of the salivary glands. How saliva is
always being produced and we keep swallowing.  If we do not swallow
for a few minutes, our mouths become filled with saliva.  Then, when
we do swallow, our mouth feels relatively empty, but immediately we
will feel more saliva trickling in.  I have reservations about
discussing spit analagously with breastmilk, but.....?
                                                Susan Mocsny Baker,
RNC