字幕列表 影片播放 列印英文字幕 Dnews audience member, Stephan, wants to know, "Why do men have nipples?" to which science says, "Psh. Why not?" Hey friends, Laci Green here with a very important topic, male nipples. Men don't feed babies with their boobs so why are they there? The basics go like this. In the womb, a sperm meets the egg and a zygote is formed. All your genetic information is tightly packed into 23 pairs of chromosomes. One of those pairs determines your sex. XX for females and XY for males. There are other sex chromosome pairings like XXY and XXYY, but hey, that's a whole other video. The other 22 pairs of chromosomes provide the genetic blueprints to make a human being. Information about how to form your feet, and your heart, and your eyes, and your nipples. In the third or fourth week, you're a little embryo, chilling in the womb, and that's when the nipples begin to develop. It starts with the milk line, which runs from your armpit down through your breasts to your genitals. Typically only two nipples are arranged on the milk line, but as many as seven can line up and come hang out. For most people, these don't develop any further, but sometimes they do and people are born with more than two nipples. You can also have little remnants that looks like moles, but they're actually just teensy embryo nipples. Now not only do you get nipples but also get milk ducts. At this point, everyone's looking pretty female. That is until the eighth week when the hormones start pumping. For males testosterone mean the penis starts to develop out from the clitoris. The scrotum develops out from the labia. Things like where you'll get body hair, and how deep your voice will be is determined. You already have nipples and milk ducts, but the hormones determine if you'll develop more breast tissue. This happens much later though during the next hormonal uproar in your lifetime, puberty. So if males do have nipples and mammary glands, couldn't they produce milk? Aha! Yes they could, but they're missing the proper hormones to do so. Hormone are the law of the land. No hormones means no milk. Sometimes on rare occasions, males will spontanesouly produce milk later in life. It's called Galactorrhea, which is a pretty epic name to be honest. Sometimes that happens in infants too, right after they're born. When doctors can figure out the cause, it's usually a hormonal thing: not enough testosterone, extra estrogen, extra prolactin, which is the milk producing hormone. But a nice chunk of cases, scientists don't know why. It's just one of those cool nature things that remind you, sex isn't quite as clear cut as it seems to be. Thanks for joining me, guys. Do you have a question for me, Anthony, or Trace? You should leave it in the comments down below and hey, maybe we'll make a video for you. Don't forget to subscribe for more Dnews updates, and we'll catch you next time!