An image showing the anatomy of milk ducts went viral this week, leaving people in mixed states of shock, confusion and fascination.
It’s been a big week in boobs news. Twitter user @lemonadead shared an image of the anatomy of milk ducts along with the caption: “I just realised I never saw a photo of a female muscle system. This is NOT what I imagined milk ducts to look like.”
Within five days, it received 45,605 retweets and over 138,000 likes. Basically, people are obsessed with the ducts, which carry milk to the nipple after childbirth, forming a flower-like shape on each breast. Many are calling them beautiful, whereas others are a little bit freaked out. One thing that most people can agree on is: shouldn’t we already be familiar with this image?
Well, some are arguing that the ducts aren’t included in muscle anatomy photographs shown in school text books because they are actually glands. One male Twitter user wrote: “Those aren’t ‘milk ducts’ they are mammary glands and the reason you have never seen them is because they aren’t muscle. So having a model that shows the entire muscular system and one gland is… odd.” But Dr Sarah Taber, an American crop scientist and former farm worker with extensive knowledge in milking and mammals, has shut down these mansplaining comments on the female anatomy with an educational Twitter thread.
“Here’s the thing, folks: the lobes/ducts of mammary glands are covered in smooth muscle because boobs do not work like people think they do,” she explained, linking to information provided by the National Center for Biotechnology. “Folks think milk comes out because of suction, it does not! It’s ejected by smooth muscle surrounded the mammary glands & ducts. This is initiated by oxytocin and it’s called the let-down reflex (e.g. when the glands ‘let down’ the milk).
“Oxytocin interacts a lot with social bonding and relaxation. It does lots of things. For now the main thing about it is that it’s released by many things, including… hanging out with your baby! In a relaxed environment! And also nipple stimulation.”
Dr Taber continued: “The vast majority of milk cannot come out of a mammary gland through suction. It has to be ejected out. You can *try* and put a vacuum big enough to suck it all out, but you’d mostly just distort and destroy the tissue instead. So the job of babies, pumps, and milking assemblies *isn’t to suck milk out of the glands*. It’s to stimulate the tissues enough to release oxytocin, at which point the mammary muscles do the work of ejecting milk themselves. And that’s why muscle diagrams include milk ducts.”
She added: “Anyway, that’s why a proper muscle diagram SHOULD include mammary gland assemblies. Transwomen and cis men have them too. Men just don’t have as much extra fat around the glands, which is what most of what the human breast is made of.”
The much-needed lesson ended with: “So for the folks goin off about “how dare they put boobs on MY MUSCLE DIAGRAM,” sorry folks! That’s the real deal anatomy. Those muscle-only chest walls we’ve been seeing our whole lives, without the mammary glands? THEY’RE the redacted, politically correct version.”
Image: Annie Spratt @ Shutterstock