Sex Organ Up Your Nose

Sex Organ Up Your Nose
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We humans have a bunch of highly-developed senses, but most of our communication happens with sound and vision. Not much communication between people happens with smell. But now we are beginning to prove that we humans can influence each other with our smells - and, that we pick up these smells with a strange sex organ inside our noses!


The anatomy scientists have known for a long time about the "olfactory
epithelium". "Olfactory" means "related to smell". The olfactory epithelium is a patch of yellowish tissue high up in "ceiling" of the nose. Normally, it is poorly ventilated, but when we sniff deeply, we pass lots of air over it. In this yellow patch, there are sensory cells specially adapted for smelling. Chemicals in the air enter the nose, excite the sensory cells, and then we get the sensation of "smell".


There is also another area in the human nose that we can detect odours with - but until recently, most scientists didn't believe it existed! This is the VNO, which stands for "vomeronasal organ". Fishes, birds, and some mammals don't have a VNO, but it is very well developed in snakes and lizards.


It was first discovered by the Dutch anatomist, Ruysch, way back in 1703. It's right next to the wall that separates the nostrils, on the quot;floor" of the nose, and about a centimetre inside the nose. There's one in each nostril. It looks like a hollow tube, with only a very small opening (about one tenth of a millimetre across) into the nose. Each VNO is very small, and hard to see.


This might be why the vomeronasal organ fell out of favour, and soon the anatomists didn't even believe it existed. By the 1930's, physiologists said hat not only did we humans definitely not have a VNO, but there was no structure in the brain to process the information from any such organ. However, in 1991, a careful study found that 910 out of 1,000 people had an easily-found VNO. But the fact that we humans have a vomeronasal Organ, does not mean that it does anything.


In 1994, Luis Monti-Bloch and his team from the University of Utah actually managed to thread very fine insulated electrical wires into the VNOs of volunteers. They then wafted various smells up the noses of their volunteers, and looked for electrical activity in the cells of the VNO. These smells were various odourless chemicals from the skin of men and women. The volunteers had absolutely no conscious idea that they were getting these smells - in other words, their olfactory epithelium which smells perfumes and pollutants, did not trigger. The cells in the males' VNOs fired when they got female skin smells, and female VNOs responded to male skin smells. But the VNOs did not respond to skin smells from the same sex.


It was odd that the volunteers didn't consciously realise that their VNO was being stimulated. We can waft a smell up their nose, and their VNO can fire frantically with electrical activity - but all the volunteer gets is a vague, generalised emotion of feeling fine.


But in early 1998, an excellent experiment showed a more definite effect - that some female smells could trigger women's menstrual cycles. Kathleen Stern and Martha McClintock from the Psychology Department at the University of Chicago did the experiment. They had some "donor" women, who gave away the smells in their armpits (via a pad that they wore for 8 hours per day). They also had some "recipient" women, who were exposed to these smells. The smells were completely odourless, as far their conscious brains were concerned. And of course, the two groups, donors and recipients, never met face-to-face.


The smells were taken from the donor women at two different times in their menstrual cycle. When the smells were taken before the donors ovulated, the ecipient's menstrual cycles became shorter. But when the smells were taken right on the donors' ovulation, the recipient's menstrual cycles became longer. The overall effect was to synchronise the cycle of the recipient, with the cycle of the donor.


This was a pretty good experiment, but we're still not 100% sure that the smells from one human can influence another human. For one thing, this effect happened to only 70% of the volunteers - so what's going on in the remaining 30%? For another thing, our neuroanatomists have not yet proved that nerves from the human VNO go to the relevant parts of the brain. The only way to do that is to get several corpses, add some dye to the VNO, and wait a few month for the dye to migrate, and then very carefully cut open the brain.


So if your boyfriend or girlfriend gets up your nose, it may not be their
fault.

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