b. The Internal Structure. The inner components of the breast are comprised
of fibrous, glandular, and fatty tissue. They are augmented by a segment of the
vascular system that includes a rather extensive lymphatic network. The intercostal and
pectoral muscles form the breast wall.
(1) The fibrous tissue consists of two layers of fascia suspensory ligaments
and an irregularly-pitted framework for the glandular tissue. The fascia layers,
superficial and deep, are joined and completely house the mammary gland. The
suspensory ligaments are vertical hands of elastic fibrous tissue that pass through the
glandular tissue and connect the deep layer of fascia with the skin. The remainder of
the fibrous tissue comprises the honeycombed framework for the mammary gland.
(2) The mammary gland consists of 15 to 20 lobes, each of which is
composed of numerous lobules. All are interconnected by the lactiferous ducts, which
form a distinct network. The tiny ducts from the lobules, called terminal ducts or acini,
empty into the larger main ducts. These, in turn, empty into the lactiferous tubules that
extend from each lobe into the nipple.
(3) Fatty tissue completely surrounds and is distributed in the glandular
tissue in varying amounts, depending upon the patient's age and obstetrical condition.
Figure 4-2 shows the internal structure of the breast.
Figure 4-2. Internal structure of the breast.