Just found this stored in draft form in my files. I put too much thought
into it not to share it, even though the thread was weeks and weeks ago.
I hope some of you agree.

Catherine, (Fetherstone)

I have been thinking over what you wrote:

<I would however like to suggest that based on what we know of breast
anatomy (or probably more precisely what we don't know) I don't think we
can assume because a women has a larger sized breast that she will have a
more extensive ductal system to carry the milk.>

I agree that every woman, and perhaps each of the 2 separate breasts on
every woman is individual. and fat makes up for a lot of the size of the
non-pregnant breast, and often the pregnant and lactating breast as well.


<Someone may correct me on this but I'm not aware of any research that
tells us how glandular tissue is distributed within the breast in regard
to - if you have a larger breast most of the alveoli will  be situated at
the very back of the breast which
would necessitate "longer tubes". It's possible that large breasted women
may predominantly have most of their milk producing tissue in the middle
of
the breast or at the front or in a combination of all three.  It may also
vary widely between breasts and between individuals. The thing is we just
don't know.>

I agree there is a lot we don't know. Kathy Dettwyler posted once to me
about Mali women with breasts so long they could sling them over their
shoulders and the baby could still nurse.

I asked her where she thought the glandular tissue was in those breasts,
but she was unable to say (as anthropologists job descriptions certainly
do not include palpation of the breasts :-)

During pregnancy, while the outer appearance may be relatively the same,
with some noticeable increase in size and circulation, much of the fat is
replaced with newly formed glandular tissue, "sprouting" off of the ends
of the "TDLU", or terminal ductal lobular units, of the already
established ductal system.

These may extend off the ducts, from the diagrams in histology texts,
pretty much anywhere along the middle and upper parts of ducts, but the
larger numbers of lobules appear to be distributed at the upper parts of
the ducts.

Of course, if the Cooper's ligaments are "sprung" so to speak, then that
area may not be as close to the chest wall.

But generally speaking, my clinical observations lead me to believe that
mothers with more pendulous breasts do seem to have longer ductal
tubings, though not necessarily as many separate ducts as mothers with
smaller sized breasts may or may not have.

Here is an example of what I had in mind with my original post on this.
The references say the average breast has 15-20 lobes.

Let's say someone with a B cup has 20 lobes in each breast. That would
probably mean 20 ducts  joining into about 10 milk sinuses, with 10 holes
in the nipple. (I believe this convergence of ducts is something emerging
from Donna's ultrasound research with Dr. Hartmann.) This mother would
have a large storage capacity, but in 20 different shorter ducts.

She could still have an OALD (overactive let down), and even an
oversupply, but I would think the force of the MER (stimulating
myoepithelial cells that occur both around the alveoli and surrounding
each of  the ducts) would dislodge the fat particles from the walls of
the ducts and jet them to the front more easily in the less pendulous
breast while it was at the same time ejecting the "newly minted" milk
stored in the lobule.

"Lobule" is the histological name of the smallest clusters of alveoli
plus their collection area. This newly secreted milk must exit through a
very tiny ductule, the first tube off of the lobule, leading into the
collecting ducts.

(The tininess of the ductule, I think, is the reason the skim milk can
trickle on through it, but the largeness and generally spherical shape of
the fat globules requires the force of the MER to change their shape
enough to force them through the ductules to the collecting ducts.) But
this, too, would then have a shorter distance to go before reaching the
nipple in a B cup breast.

In contrast, for example, say a mother with EE cups who might have just
15 lobes (or fewer) in each breast, joining together to form 7 or 8
sinuses, with 7-8 nipple holes.

She too, might have a large total storage capacity, (or not), but each of
the tubings would be longer (but perhaps thinner in some) since her
pendulous breast means she'd have a longer distance from the bulk of
glandular area to the nipple. Her milk sinuses might be further from the
base of the nipple, but they could just as well be close to it.

She also might or might not have OALD, but any fat globules, either
adhered to the duct walls, or newly ejected from the ductules, would have
a longer distance to traverse before reaching the nipple.

I really think these are the moms who, if single pumping, would be the
ones more likely to get watery looking milk on the first side when it has
been a long time since last pumping/MER. Then, the milk on the second
side pumped, would have more opaque white or ivory color due to it's not
having been pumped till after at least one MER to redistribute more fat
particles forward.

<Just as an example of how much we don't know - Donna Ramsay who is the
ultrasonographer conducting research into let down, ductal size and
placements etc told me she has in one of her mothers isolated a duct
(using ultrasound) that appears to initiate in a certain part of the
breast and found that it meanders over to the other side of the breast
and comes back again before draining into a nipple pore. I for one have
always visualised this very neat diagrammatic arrangement that we see so
often depicted - of
the alveoli, grouping into lobules and draining straight to the nipple.>

I find this new research fascinating, and am eagerly awaiting any
publications. Please alert us as soon as you learn of any.

< I believe the morphology that we currently base our knowledge on was
done on cadavers a very long time ago. It's probably time we started to
review this "knowledge".>

Since that original research on cadavers, there have been literally
millions of breast surgeries and histological exams done under the
pathologists' and surgeons' microscopes. Overall interpretation of their
literature is far beyond my ability, but now and then, a diagram or a
description adds to my insights.

Certainly, these examinations take place because of some degree of
pathology in the first place, and relatively few would have been done on
the pregnant or lactating breast. But nevertheless, this literature, plus
the radiologic literature with it's descriptions of ductography, has been
fascinating for me to delve into.

I have found many simplistic "generic" diagrams with misleading depiction
of the milk sinuses and ductal patterns that almost remind us of "bicycle
spoke" regularity, especially in lactation related texts and articles and
breast teaching models.

< Certainly this finding of Donna's has made me think a little
differently about duct placement and perhaps for some women may provide a
clue as to why they experience repeated blockages in specific areas.>

During the time this draft has been hiding in my files, I found this
quote:

"Consequently it is not surprising to find that the amount of milk that
potentially can be stored increases with breast size. Indeed, although we
were  not able to quantify the relationship, we observed that the
measured storage capacity of a breast increased with breast size." (p.
32.)

"Infant Demand and Milk Supply. Part 2: The Short-term Control of Milk
Synthesis in Lactating Women", Steven E.J. Daly, PhD and Peter E.
Hartmann PhD, J Hum Lact 11 (1) 1995 , p. 27-37.

Jean
***********
K. Jean Cotterman RNC, IBCLC
Dayton, Ohio USA

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