Welcome to this lecture on “The Breast”.
This slide lists the learning objectives that
you should be able to answer at the conclusion
of this presentation.
Describe the external features of the breast.
Describe the tissue elements of the breast.
Describe the neurovasculature and lymphatic
drainage of the breast.
List the frequencies of cancer by location
in the breast.
Describe a sentinel node biopsy and its clinical
Describe nerves that are vulnerable during
Describe how the milk line explains variations
in the breast.
And then we'll finish up by identifying the
key take-home messages in the summary.
And then we'll provide attribution for the
images that are used throughout this presentation.
Here is our body map and our focus will be
on the area that we see in through here and
then on the left as well.
And our first slide, this slide depicts
the gross appearance of the breast. It is
an anterior view. The most conspicuous structure
is this pigmented area, referred to as the
areola, and in its center, you have an elevation
and that elevated region is the nipple.
If you take a look within the pigmented areola,
you will see some bumps and these bumps that
you see are sebaceous glands that are referred
to as areolar glands. And their oily secretion
will help lubricate the areola as well as
the nipple and this is essential, particularly
if the mother is nursing her infant.
Here we're looking at the breast in a lateral
view. The breast is said to overlie ribs 2,
3, 4, 5 and 6. It will generally run from
the sternum to the midaxillary line. And in
the lateral view, our midaxillary line would
be approximately in this location. However,
in this particular individual, the breast
tissue does not quite make its way that far
posteriorly because there is variability and
that variability is due to variations in breast
In addition, the nipple is said to overlie
the 4th intercostal space. This is a more
constant location in men. However, because
of differences in breast size and the effects
of aging, the nipple may be at a lower relationship.
And if the breast does extend more toward
the midaxillary line, that extension of breast
tissue is referred to as the axillary tail
or you can say the axillary tail of Spence.
Spence is utilizing the eponym.
The breast harbors various types of tissue
elements and the breast will sit or reside
on the fascia that covers the pectoralis major
muscle. So, if we take a look here, we see
the pectoralis major and then between the
breast itself and the pectoralis major, throughout
most of where it's located, that breast will
sit on this pectoral fascia.
The tissue elements within the breast, and
again, these will be variable between women,
you will have adipose tissue. And so, we see
variable amounts of adipose tissue in this
illustration. You'll also have variable amounts
of connective tissue, which is shown here
as these white components within the illustration.
And these white components will attach to
the surface of the skin, as you see here,
for example, and as you see here.
And these fibrous connective tissue components
are referred to as the suspensory ligaments
of the breast, also known as Cooper's ligaments.
And then you'll have variable amounts of glandular
tissue. And we see glandular elements, or
profiles, throughout this illustration. And
then these glandular profiles will have ductile
components that will converge onto the nipple
and you see some ducts. These are lactiferous
ducts. You'll have 15 to 20 of these converging
toward the nipple and as they make their way
toward the nipple, you'll see that there's
a dilatation here. That dilatation is the
lactiferous sinus and then, for a short distance
thereafter to the surface of the nipple, that
that will narrow again.