In the Name of God, the Most Merciful, the Most Compassionate What is the Breast? Breast Definition: a modified sweat gland (sometimes called skin gland) present in both genders, well developed in females but functionless in males. Location: it s located within the superficial fascia of the anterior aspect of pectoral region. It doesn t have a special capsule. Shape: round contour (spherical). Its shape and volume are due to the presence of subcutaneous fat. During pregnancy, there s another reason for the big volume (mentioned later). The Breast is Composed of: Overlying skin: It's the covering part. Secretory (mammary) glands: Responsible for milk secretion. Loose connective tissue: Supporting the ducting system (secreting parts). Dense connective tissue: Seperating (partitioning) lobes. Fat tissue (adipose tissue): For size, flexibility, and free movement. It also saves the breast contents from occlusion. 1 P a g e
How is the Breast Attached to the Skin? The breast is firmly attached to the skin by suspensory ligaments (clinically known as Cooper s ligaments, named for their discoverer), which are connective tissue in the breast that help maintain structural integrity. These ligaments are well developed in its upper part as they re attached to the skin s dermis, assisting in the support of breast tissue. In the lower part, the breast is pendulous and not supported by these ligaments. Consequently, the breast is supported superiorly, but not inferiorly. Clinical Application: With inflammatory breast cancer, the breast skin has a thick, pitted appearance that is classically described as peau d orange (resembling an orange peel). In this case, connective tissue of suspensory ligaments shrinks, pulling the skin (which is the weakest part of the breast) and giving it the pitted appearance. Location of Breast: It s located anterior to pectoral muscles (pectoralis major and pectoralis minor), thoracic wall, and a space filled by loose connective tissue called retromammary space. Retromammary space, which is located between pectoral fascia (a fascia covering pectoralis major) and the breast, 2 P a g e
contains small amount of fat in order to allow the breast to move during lactation. Mature Breast: Remember: After female puberty, so many changes are happening: the period starts, the ovaries begin producing chemicals called estrogen and progesterone, and the breasts begin to develop and become mature breasts. The light brown colored nipple is surrounded by a circular pink area called areola. Once the lady is pregnant, the areola will be dark in color and never changes back. It may fade (lighten) a little bit after delivery, but remains dark due to multiple hormones secreted during pregnancy. Base of the mature female breast extend from lateral border of sternum to midaxillary line (from medial to lateral), and from the 2 nd to the 6 th rib (from superior to inferior). Clinical Application: After marriage, the color of the areola changes from pale pink to dark brown. This mark is much used in legal medicine. 3 P a g e
Contents of Mature Breast: 15-25 lobes radiating from the nipple (they look like spokes of wheel). Lobes are separated by septums ( sespensory ligaments) Each lobe is formed of numerous secretory lobules drained by series of ducts that unite to form one terminal lactiferous duct opened to the nipple. Before reaching the nipple, the duct dilates as lactiferous ampulla ( sometimes called lactiferous sinus), then narrows to reach the nipple. Lobules and ducting network are embedded in loose connective tissue that contains variable amounts of fat tissue, which contribute to the increase of breast size at puberty. When a woman is not lactating, the lactiferous duct is frequently blocked by a keratin plug. 4 P a g e
Note Do NOT mix up between the lactiferous ampulla, and the ampulla of the uterine tube! Arteries and Veins to Breast: Remember: Axillary artery is a direct continuation of subclavian artery. Each is divided into three parts. Thoracoacromial artery and lateral thoracic artery arise from the second part of axillary artery. Arteries to Breast: 1. Branches of the second part of axillary artery (thoracoacromial artery and lateral thoracic artery). 2. Perforating branches of internal thoracic artery, which is a branch of the first part of subclavian artery. 3. Intercostals arteries from thoracic aorta. (The aorta, which is the largest artery in the body, is described in several portions: the ascending aorta, the arch of the aorta, and the descending aorta, which last is again divided into the thoracic and abdominal aortae ). Veins to Breast: Same names, reverse directions of arteries! Breast Quadrants: Breast is divided into four quadrants. These quadrants are important for the precision of clinical examination, and to determine the exact location of cancerous cells. 5 P a g e
Upper Lateral Upper Medial Lower Lateral Lower Medial Lymph Drainage of Breast: Remember: Lymph vessels carry the waste products (products of metabolism) from the intercellular spaces to the lymph nodes to do filtration for these products. The axilllary nodes are generally divided into five groups on the bases of location. It is important because of its role in spreading of cancer cells (called Metastatic Cancer which is cancer that has spread from the place where it first started to another place in the body). Approximately 75 % of the lymph from the breast (from the lateral quadrants) travels to the anterior axillary nodes located at the lower border of pectoralis major. Lymph from the medial quadrants of the breast travels to the internal thoracic nodes which accompany the internal thoracic artery. (Most remaining). Few of the lymph will travel to the posterior intercostals lymph nodes. 6 P a g e
Some of the lymph will communicate with the opposite breast, and with the anterior abdominal wall. Breast Development: At birth, the breast is very immature. During puberty, the breast gradually enlarges due to fat deposition and glandular growth, and takes its hemispherical shape influenced by ovarian hormones. Also, the ducts elongate. In the early months of pregnancy, breast shows: rapid increase in length, more branching in the duct system, proliferation of secretory alveoli at the ends of terminal ducts, 7 P a g e
preparations for milk secretion, increased vascularity of connective tissue. In addition, nipple enlarges and areola becomes darker. During second half of pregnancy, the growth process slows. Breast continues to enlarge, but mostly due to destention of secretory alveoli. At this stage, the breast secretes a form of milk called colostrum (or first milk). Colostrum contains antibodies to protect the newborn against disease, as well as being lower in fat and higher in protein than ordinary milk. During post lactation (weaning stage), breast returns to its inactive state. The secretory alveoli shrink and most of them disappear, the interlobular connective tissue thickens, the breast shrinks and returns nearly to its original size. Remaining milk is absorbed, and pigmentation of areola may fade (but doesn t return back to its original color). 8 P a g e
Notes: 1. Babies fat is brown because it s full of nuclei and mitochondria. Ours is yellow! 2. Axillary tail is an extension of the tissue of the breast which extends into the axilla. Finished! Best wishes from me to you! Your colleague: Aseel Nsairat. The boy didn't know what a person's "destiny" was. "It's what you have always wanted to accomplish. Everyone, when they are young, knows what their destiny is. At that point in their lives, everything is clear and everything is possible. They are not afraid to dream, and to yearn for everything they would like to see happen to them in their lives. But, as time passes, a mysterious force begins to convince them that it will be impossible for them to realize their destiny... It's a force that appears to be negative, but actually shows you how to realize your destiny. It prepares your spirit and you will, because there is one great truth on this planet: whoever you are, or whatever it is that you do, when you really want something, it's because that desire originated in the soul of the universe. It's your mission on earth. And remember, when you really want something, the universe always conspires in your favor" Paulo Coelho - The Alchemist Old king to Santiago 9 P a g e