Ooops!  It's hard to think in three dimensions at this hour of the morning.

Let me take back what I said about the baby's nursing creating a "whoosh"
against the downstream side of a plug.  Of course, of course, the direction
of pressure that a baby's nursing exerts is always (from the baby's point of
view) distal to proximal---tip of the tongue INTO the mouth---and (from the
mother's point of view) proximal to distal---inside the breast OUT TOWARDS
the nipple.

Maybe I need a different analogy.  A stream of water has to stay where it is,
but a milk duct is a flexible tube.  It's like your vacuum cleaner hose that
gets a plug of dog hair stuck in it.  (I thought about this as I was walking
Martha, my faithful 10 yr old mutt.)  Massaging is like squeezing and bending
the hose, changing its shape in hopes of dislodging the plug, or breaking off
parts of it.  Depending on how far the plug is from the nipple---how far back
upstream in the breast---the baby's tongue may or may not be able to exert
direct pressure on and around it.  But the mom's fingers can reach any plug
that is near the surface and massage it.

Now if you're picturing a vacuum cleaner, please remember that I'm NOT
talking about suction, as in *Baby sucks breast and milk comes out* like dust
being sucked INTO the vacuum cleaner.  I just chose the analogy because lots
of people have coped with a clogged vacuum cleaner hose.  The milk duct would
be more like a garden hose---fluid runs through it under pressure---but
(luckily) we don't have impurities in our water system big enough to clog a
hose (not yet, anyway), so that image isn't as accessible for me.

Pointing the baby's nose toward the plug is like putting your vacuum cleaner
hose under a sofa cushion and trying to work on the plug through the cushion.
 (The cushion is like the thickness of the breast between the baby's tongue
and palate.) There's diffuse pressure everywhere, but less direct pressure on
the plug itself.  Pointing the baby's chin toward the plug is like laying the
hose on top of the cushion and working on it with your hand.

Of course, what you don't want to do is squeeze the whole hose firmly from
all sides while you try to dislodge the plug.  That's what swelling in the
area does---just packs everything tighter.  I would imagine that the pressure
from swelling also tends to dry out the plug, making it a firmer consistency
and more difficult to break up.  Women have reported squeezing out elongated
plugs that looked like short pieces of spaghetti, and one woman told me she
expressed hard things like little diamonds.  I asked a dairy physiologist
about this later, and he told me that, yes,indeed, cows do get milk stones
sometimes.  Knowing what we know about how painful kidney stones and gall
stones can be, we know that we don't want plugged ducts to go this far!

Another thing about the MER, though, is that myoepithelial cells along the
ducts contract to make the ducts *shorter and wider* under the influence of
oxytocin.  That would be like having a way to widen your vacuum cleaner hose,
loosening the plug and allowing the vacuum to pull it through.

That's enough for now.

Chris