7 Surprising Facts About the Breast

The human body is an amazing thing. For each one of us, it's the most intimate object we know. And yet most of us don't know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow. Of all the organs of the body, the humble breast has come to represent so much more than its essential functions. American culture places undue value on size, shape, and appearance of breasts, which can make it easy to forget the essential function of the breast, from an evolutionary standpoint, which is primarily for feeding our offspring. Mental Floss spoke to a pair of specialists about the breasts. Here are seven things we learned.


Beneath the fleshy mound that we think of as a breast is the less glamorously named mammary gland, a complex network of fat cells and tubes that are capable of producing milk for babies. If a woman becomes pregnant, the milk ducts, sac-like structures, fill first with colostrum before the baby is born and then breast milk after, and send it via little channels called lobules to the nipple, where the milk exits.


According to Constance Chen, a plastic and reconstructive surgeon and director of microsurgery at New York Eye & Ear Infirmary of Mount Sinai Hospital, two breasts are rarely, if ever, identical. "Breasts come in all shapes and sizes," she tells Mental Floss. "There are lots of different ways to be normal." The same is also true for nipples and their areolae, the darker colored skin around the nipples.


An inverted nipple is a normal occurrence "caused by adhesions at the base of the nipple that bind the skin to the underlying tissue," according to a team of specialists at Columbia University that answers medical questions in a column called "Go Ask Alice." It's possible to have one inverted nipple and not the other, or both. In general, it should cause very little discomfort or problems, with the exception of breastfeeding. Sometimes an inverted nipple can be difficult for an infant to latch onto, but there are methods to help the nipple protrude again, such as nipple shields. In very rare cases, a nipple that becomes inverted may be a sign of breast cancer, in which a tumor is pulling on the tissue and causes it to invert.


Many women blame breastfeeding for breast droop, but the facts don't bear that out. While pregnancy can change the elasticity of ligaments in the breasts, breastfeeding merely changes the size of the breasts, but has little impact on the elasticity of the skin. Smoking, on the other hand, is a direct antagonist to elastin, the substance that makes all skin supple, which can lead to drooping breasts.


People often believe that the only way they're likely to get breast cancer is if they have a family history. According to Chen, this is not accurate: "Most people who get breast cancer have no family history," she notes. Beyond genetics, risk factors include "getting older, benign breast problems, more exposure to estrogen, drinking alcohol, and exposure to radiation." And men can get breast cancer, too. "It makes up less than 1 percent of all cancers in men, but it's not a part to be ignored," Jay Harness, a breast cancer and reconstructive surgeon at St. Joseph Hospital in Orange, California, tells Mental Floss. Women and men should both seek preventative cancer screenings, especially if there is a family history of the aggressive BRCA1 gene that carries a significant risk of cancer in men and women. Early detection is key to helping treat breast cancer.


According to a class at Stanford titled "A History of the Body," early midwives and medical practitioners made meaning of the colors of women's breasts. A 17th-century midwife, Jane Sharp, wrote about the English women she tended to: "The Nipples are red after Copulation, red as a Strawberry, and that is their Natural colour: But Nurses Nipples, when they give Suck, are blue, and they grow black when they are old."


Psychologists from the University of Nebraska-Lincoln did a study in 2013 to determine whether men were alone in their alleged fascination with women's breasts. For the study, titled "My Eyes Are Up Here: The Nature of the Objectifying Gaze Toward Women," 29 women and 36 men were fitted up with eye-tracking technology and shown women with "body shapes that fit cultural ideals of feminine attractiveness to varying degrees." They were told to focus on the appearance versus the personality of the women. Both male and female participants spent more time looking at the women's breasts than they did their faces, especially if a woman had a "high ideal" body shape: hourglass, with a small waist and large breasts.

10 Facts About Your Tonsils


Most of us only become aware of our tonsils if they become swollen or infected. But these masses of lymphatic tissue in the mouth and throat are important immunological gatekeepers at the start of the airways and digestive tract, grabbing pathogens and warding off diseases before they reach the rest of your body. Here are some essential answers about these often-overlooked tissues—like what to do when your tonsils are swollen, and whether you should get your tonsils removed.

1. People actually have four kinds of tonsils.

The term tonsils usually refers to your palatine tonsils, the ones that can be seen at the back of your throat. But tonsillar tissue also includes the lingual tonsil (located in the base of the tongue), tubal tonsils, and the adenoid tonsil (often just called adenoids). "Collectively, these are referred to as Waldeyer's ring," says Raja Seethala, the director of head and neck pathology at the University of Pittsburgh Medical Center and a member of the College of American Pathologists Cancer Committee.

2. Tonsils are one of the body's first responders to pathogens.

The tonsils are a key barrier to inhaled or ingested pathogens that can cause infection or other harm, Seethala tells Mental Floss. "These pathogens bind to specialized immune cells in the lining—epithelium—to elicit an immune response in the lymphoid T and B cells of the tonsil," he says. Essentially, they help jumpstart your immune response.

3. Adenoid tonsils can obstruct breathing and cause facial deformities.

If the adenoid tonsils are swollen, they can block breathing and clog up your sinus drainage, which can cause sinus and ear infections. If adenoids are too big, it forces a person to breathe through their mouth. In children, frequent mouth breathing has the potential to cause facial deformities by stressing developing facial bones. "If the tonsils are too large and cause airway obstruction, snoring, or obstructive sleep apnea, then removal is important," says Donald Levine, an ear, nose, and throat specialist in Nyack, New York. Fortunately, the adenoids tend to get smaller naturally in adulthood.

4. As many of us know, sometimes tonsils are removed.

Even though your tonsils are part of your immune system, Levine tells Mental Floss, "when they become obstructive or chronically infected, then they need to be removed." The rest of your immune system steps in to handle further attacks by pathogens. Another reason to remove tonsils besides size, Levine says, is "chronic tonsillitis due to the failure of the immune system to remove residual bacteria from the tonsils, despite multiple antibiotic therapies."

5. Tonsillectomies have been performed for thousands of years ...

Tonsil removal is believed to have been a phenomenon for three millennia. The procedure is found in ancient Ayurvedic texts, says Seethala, "making it one of the older documented surgical procedures." But though the scientific understanding of the surgery has changed dramatically since then, "the benefits versus harm of tonsillectomy have been continually debated over the centuries," he says.

6. ... and they were probably quite painful.

The first known reported case of tonsillectomy surgery, according to a 2006 paper in Otorhinolaryngology, is by Cornélio Celsus, a Roman "encylopaediest" and dabbler in medicine, who authored a medical encyclopedia titled Of Medicine in the 1st century BCE. Thanks to his work, we can surmise that a tonsillectomy probably was an agonizing procedure for the patient: "Celsus applied a mixture of vinegar and milk in the surgical specimen to hemostasis [stanch bleeding] and also described his difficulty doing that due to lack of proper anesthesia."

7. Tonsil removal was performed for unlikely reasons.

The same paper reveals that among some of the more outlandish reasons for removing tonsils were conditions like "night enuresis (bed-wetting), convulsions, laryngeal stridor, hoarseness, chronic bronchitis, and asthma."

8. An early treatment for swollen tonsils included frog fat.

As early practitioners struggled to perfect techniques for removing tonsils effectively, another early physician, Aetius de Amida, recommended "ointment, oils, and corrosive formulas with frog fat to treat infections."

9. Modern tonsillectomy is much more sophisticated.

A common technique today for removing the tonsils, according to Levine, is a far cry from the painful early attempts. Under brief general anesthesia, Levine uses a process called coblation. "[It's] a kind of cold cautery, so there is almost no bleeding, less post operative pain, and quicker healing. You can return to normal activities 10 days later," Levine says.

10. Sexually-transmitted HPV can cause tonsil cancer.

The incidence of tonsillar cancers is increasing, according to Seethala. "Unlike other head and neck cancers, which are commonly associated with smoking and alcohol, tonsillar cancers are driven by high-risk human papillomavirus (HPV)," he says. "HPV-related tonsillar cancer can be considered sexually transmitted."

26 Amazing Facts About the Human Body

Mental Floss via YouTube
Mental Floss via YouTube

At some point in your life, you've probably wondered: What is belly button lint, anyway? The answer, according to Mental Floss editor-in-chief Erin McCarthy, is that it's "fibers that rub off of clothing over time." And hairy people are more prone to getting it for a very specific (and kind of gross-sounding) reason. A group of scientists who formed the Belly Button Biodiversity Project in 2011 have also discovered that there's a whole lot of bacteria going on in there.

In this week's all-new edition of The List Show, Erin is sharing 26 amazing facts about the human body, from your philtrum (the dent under your nose) to your feet. You can watch the full episode below.

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