GUIDES
Thorax: Mammary Gland
[Plate 176, Mammary Gland]Consists of glandular tissue in which the majority is embedded within the tela subcutanea (superficial fascia) of the anterior chest wall
overlying the pectoral muscles.
The glands are rudimentary in males and immature females.
Size and shape of the adult female breast varies; the size is determined by the amount of fat surrounding the glandular tissue.
The base of the breast is fairly consistent extending from the lateral border of the sternum to the midaxillary line and from the 2nd to the 6th
ribs.
The majority of the breast overlies the deep pectoral fascia of the pectoralis major muscle, with the remainder overlying the fascia of the
serratus anterior.
The breast is separated from the pectoralis major muscle by the retromammary space, a potential space filled with loose connective tissue.
The breast is firmly attached to the overlying skin by condensation of connective tissue called the suspensory ligaments (of Cooper), which
help to support the lobules of the breast.
A small part of the mammary gland may extend toward the axilla, called the axillary tail (of Spence).Structure of the Breast
For descriptive purposes, the breast is divided into four quadrants: upper and lower lateral, and upper and lower medial.
The most prominent feature of the breast is the nipple.
The nipple is surrounded by the areola, a circular pigmented area of skin.
The areola is pink in Caucasians and brown in African and Asian people.
The pigmentation of the areola increases during pregnancy.
The areola contains sebaceous glands, following a pregnancy these secrete an oily substance to protect the mother's nipple from irritation
during nursing.
The breast is composed of 15 to 20 lobules of glandular tissue, formed by the septa of the suspensory ligaments.
The mammary glands are modified sweat glands that are formed from the development of milk-secreting alveoli, arranged in clusters.
Each lobule is drained by a lactiferous duct
Each lactiferous duct opens on the nipple.