Anatomy of the Breast
You may want to refer to the Anatomical Drawings (links are above) for specific anatomical features mentioned here.

Men and woman have breasts. Just about anything that you will find in a female breast will be found in a male breast, but some of the components will be undeveloped in the male. Men (and that includes prepubescent and pubescent males) do not expect to see any breast development on their body, unless they put on a lot of fatty deposits or they build up some fantastic "pecs". Large pecs are the result of muscular development behind the breast (pectoralis muscles), and should not be confused with breast development. Women that do exercises to increase their breast size merely increase the pectoral muscle size, which makes their chest wall measurement (above the breasts) larger. Their cup size does not change, unless they work really hard developing those pecs. Unfortunately, the change will most likely be a reduction in the cup size. Exercising muscles to develop them requires energy that may come from the burning of fatty deposits in the body, and those deposits may be those in the breasts.

When babies (males and females both) are only about three days old, a secretion called "witch's milk" can be expressed from the breast. This is thought by some experts to be caused by the excessive hormones in the mother's blood just before she gave birth. They were in her blood to allow her to produce milk. The fetus does not share the mother's blood while it is inside her uterus, but hormones, vitamins, minerals, etc. will pass through the placenta and umbilical cord to the fetus. Females may secrete a small amount of fluid from their nipples anytime after their breasts mature (and she is not pregnant or lactating). Be alarmed only if there is a sudden change in amount expressed, or its color, or if one side suddenly is different than the other side.

About 85 percent of the males will have some breast swelling during their puberty. This panics the males, and causes some concern to the parents, too. This is usually a temporary situation that exists for less than a year and a half. A call to his doctor should alleviate any concerns that anyone may have.

Males should be as aware of their breasts as females should be of theirs. Males can get breast cancer. Any unusual changes to the skin or the interior of the breast or emissions from the nipple should be brought to the attention of their doctor.

A woman's breasts will produce colostrum for the first several days after delivery of a child. This is a type of pre-milk, and "true" breast milk will follow that. See our section on Breastfeeding for further information about the production of breast milk and breastfeeding. Some men actually have successfully produced breast milk. With help from hormones and a lengthy process of physically "encouraging" the production of milk, it has happened, but it is extremely rare.

The American Cancer Society considers the human breast to be that area delineated by a perimeter line that traces from the center of the sternum (breast bone) downward to the "bra line" (under the breasts), across to the side of the body, up to the center of the armpit (axilla), and across the clavicle (bone) to the top of the sternum (breast bone). This entire area should be carefully checked when doing a Breast Self Examination.

The outside of the breast consists of the skin, the areola, and the nipple. There also are body hairs on the breast, and they may be especially prominent in the areolar area. These do not indicate that the lady is masculine. Their presence is normal, and their number and color are controlled in the same manner as any other genetic characteristic is controlled. Genetic codes predetermine the amount of hair on the breasts, as well as their color. Some "experts" tell us that the hairs should not be pulled, due to the chance of causing infections. Other "experts" tell us to use a depilatory cream, but to be certain that it will not irritate the sensitive nipple and areolar skin. Others advise us to bleach them so that they are less noticeable, while some go ahead and tell us to pull them out with tweezers. Be very careful with any method or material you might use. Some people leave them alone. Check with your doctor, and decide for yourself which method you prefer. (I would avoid the razor that some have chosen (ouch).)

The areola is the area of skin that surrounds the nipple. It is usually a different color than the skin color on the breast, and may vary from slightly darker than the skin to a very dark… nearly black. The color is usually determined by the color of the skin on the body, or the ethnicity of the person, and it will change during a person's lifetime. As women sexually mature and also when they become pregnant, the areolae usually darken. After breastfeeding is completed, they may return to nearly the same color as before the pregnancy. Their size can be as small as an inch across to several inches wide. They may even be wide enough to cover half the breast, although this is unusual. They will get wider during pregnancy, partly because the breast itself is enlarging.

A number of small bumps that surround the nipple and look like "goose bumps" are sebaceous glands, and are called Montgomery's Glands or Areolar Glands. They secrete an oily substance that lubricates and conditions the surface of the nipple and the areola. This is helpful during breastfeeding, to prevent cracking of the nipple. These Montgomery's Glands become erect in the same manner that the nipple does when it is stimulated by touch, cold, fear, sexual stimulation, etc. Very small smooth muscle tissues cause them to become more prominent (erect). This also causes the areolar tissue to become narrower, but sexual stimulation will temporarily expand the breast itself.

Unlike a baby's bottle, a real nipple has more than one hole, or pore. It actually may have as many as 15 to 25 pores, one for each Lobule in the breast. Nipples may be classified by their shape. If they come forward from the breast, they are considered to be prominent. They may also be flat, where they seem to be at the same level as the areola. Sometimes they may actually be depressed into the breast. These are referred to as "inverted" nipples. Be aware of how they are and pay close attention when you do a Breast Self Exam. Any way that they are is okay, but be concerned if they CHANGE. Check out the Breast Self Exam selection for more information on this matter. No matter what the nipple is like (flat, inverted or prominent), the shape will not prevent you from breast feeding your child.

People naturally focus on the nipple, and people that pierce or otherwise abuse their bodies are no exception. Carefully consider the circumstances of piercing the nipple before you do it. Remember that the 15 to 25 ducts that come through that nipple will be compromised by a wound that goes through them sideways. Consider waiting until after your breastfeeding years to do the piercing. Some nipples are exceptionally wide and some are exceptionally long, but some people attempt to modify their appearance by using various pieces of "jewelry" that stretches them or enlarges them. Use care and common sense when making decisions about modifying your body.

Parenchyma is the term that describes breast tissue that is involved in the production or transporting of breast milk. This includes the Lobes, which are the glands in which the milk is actually produced from the mother's blood. Sometimes referred to as alveoli or acini, these lobes are clustered on the ducts in a way that resembles grapes on the vine. When the brain signals the lobes to produce milk, it is gathered together by the lactiferous ducts and brought to the nipple area (lactiferous sinus). About two-thirds of the average pre-menopausal breast is Parenchymal tissues. The amount of this tissue that is in the breast will not change when the person gains or loses weight but the amount of fatty tissue in the breast will change. The size of the breast will not necessarily determine the quantity of milk that a woman will produce. Smaller sized breasts are usually as successful at breastfeeding as larger ones. When a woman is pregnant, the lobes develop to the point that they can produce milk. That is why the breast enlarges during pregnancy, and is the reason women (and also men) do not normally produce milk until they have gone through a pregnancy.

Just before each lactiferous duct reaches the nipple, it swells out a little, creating what is called an ampulla (lactiferous sinus). This is the only part of the breast that actually holds a reserve of milk. This milk provides an enticement to the infant, to keep it at the nipple, while the lobes start the production of more milk. The ampullae are what need to be compressed when an infant (or the woman herself) wants to express milk from the breast. The infant has a little assistance by using suction.

Parenchyma, and a little of the stroma (non-milk bearing tissue) make up the density (or the firmness) of the breast. At about the age of 35 years, the breast becomes a little less dense. This is why mammograms are not usually done until after that age. Dense breast tissue makes it difficult to see signs of breast cancer on an x-ray film.

Stroma is the term used for breast tissue that does not deal with milk production. Muscle tissue, connective (Cooper's) ligaments and fatty tissue are included in this category. We need to understand that there is nearly NO MUSCLE TISSUE in the breast. Exercise will not increase the size of the breast, because there are no muscles to develop. The pectoral muscles BEHIND the breasts can be developed, which might push the breasts forward a little more, if the muscles are developed extensively. That much exercise, however, may result in the loss of body fat, and some of it may come from the breasts, making the breasts smaller than they were before the exercise program began. The exercise may be very healthy for you, though. There are some very minute muscles in the areola that cause an erection of the nipple and the Montgomery's glands. There are some tiny muscles around the lobules that help to express the milk, but there are no other muscles in the breast.

We all know what the fatty tissue does. It makes things bigger. The average sized breast of a pre-menopausal woman is about one-third fatty tissue. Larger breasts usually only have more fatty tissue, but not more lobular tissue. Fatty tissue helps to fill out the voids and lumps of our bodies, and so it helps us to look softer, and smoother. The average woman has a higher percentage of body fat, so she will usually have a more rounded softness to her body, softer in appearance as well as touch.

Inside the breast, connecting the back-side of the breast skin to the pectoral muscles, are ligaments that make up what is called connective tissue. The ligaments are called Cooper's Ligaments, or Suspensory Ligaments. Their purpose is to provide the shape of the breast. They pull in on the skin, while the fatty tissue and the Lobules press outward. There are controversies that surround these ligaments and their function, and they bring about many questions. In the Awareness selection, we address some of them, including the actual function of a bra during the many stages of a woman's life.