Line Under Nose Above Lip – What is the Purpose of Philtrum
What is Philtrum?
The philtrum or medial cleft, is a vertical groove in the middle area of the upper lip, common to many mammals, extending in humans from the nasal septum to the tubercle of the upper lip. Together with a glandular rhinarium and slit-like nostrils, it is believed[by whom?] to constitute the primitive condition for mammals in general.
What is Philtrum Used for – Functions:
In most mammals, the philtrum is a narrow groove that may carry dissolved odorants from the rhinarium or nose pad to the vomeronasal organ via ducts inside the mouth.
For humans and most primates, the philtrum survives only as a vestigial medial depression between the nose and upper lip.
The human philtrum, bordered by ridges, also is known as the infranasal depression, but has no apparent function. That may be because most higher primates rely more on vision than on smell. Strepsirrhine primates, such as lemurs, still retain the philtrum and the rhinarium, unlike monkeys and apes.
Why Do We Have A Little Groove Under Our Nose?
We all have them, though it’s puzzled biologists for a long time as to why we do. I’m talking about that odd little groove found below your nose that runs to your top lip.
Technically, it’s known as your philtrum and it’s as ubiquitous to the human face as the nose or eyes. But what is it, and why the hell do we have it? Well fascinatingly enough, it all relates to how faces are formed within the womb during development.
What the philtrum marks is the location where different parts of the face merge into one. “It is the place where the puzzle that is the human face finally all comes together,” explains Dr Michael Mosley in a clip from the BBC program Inside the Human Body. “The three main sections of the puzzle meet at your top lip, creating the groove that is the philtrum.” The development of the face happens between months two and three of being in the womb, and if the face doesn’t form during this window, for genetic or environmental reasons, then it never will.
You can watch Dr Mosley explaining this below, as well as see an astonishing video of the face as it forms in the womb and how all the pieces eventually come together to create a recognizable human face, taken from scans of a real baby developing.