9-18. THE MAMMARY GLAND
The mammary glands are cutaneous glandular structures of the female.
a. Location. The mammary glands are located in the upper pectoral regions.
On occasion, a mammary gland may be found elsewhere along the "milk line." The milk
line extends from the axilla above to the inguinal region below.
b. Structure. Each mammary gland is made up of glandular tissue and
associated ducts. These structures are embedded in FCT and fat.
c. Lactation. During pregnancy, the mammary glands respond to the estrogens
and progesterone with additional growth. Toward the end of pregnancy, it begins to
form a fluid substance, colostrum. Within 2 or 3 days after the baby is born, the breasts
begin to secrete large quantities of milk instead of colostrum.
d. Importance of Nursing. One cannot overemphasize the importance of
nursing (breast-feeding) the newborn.
(1) Human milk is the natural food of the newborn infant.
(2) Strong psychological effects accompany nursing. This is true for both the
child and the mother.
(3) Initially after childbirth, the mammary gland secretes colostrum. Colos-
trum is not primarily a food item. In fact, the baby loses birth weight. Colostrum
consists most importantly of antibodies that protect the newborn during the first 6
months of life.
(4) A baby may develop an upper respiratory infection. During suckling, it
will inject some of the microorganisms into the milk ducts of the mammary gland. By
the next feeding, the mammary gland has produced the antibodies appropriate for that
e. Self-Examination. The female breast (mammary gland) is often a location
for tumor growth. Thus, it is important for a woman to be able to examine her own
breasts. During this self-examination, she must remember that a portion of the breast
extends up into the axilla. (This portion is called the "axillary tail.")