vomeronasal organ

3 Fun Facts About Your Canine Companions

Happy National Dog Day, y’all! We thought we’d throw around some pup-appreciation with the following dog olfactory facts for you to fetch. 

1. Besides being much more powerful than ours, a dog’s sense of smell can pick up things that can’t even be seen at all. The olfactory bulb, the area dedicated to processing smells, takes up many times more relative brain area in dogs than humans. This allows dogs to distinguish and remember a staggering variety of specific scents.

2. Everything in the street, every passing person or car, any contents of the neighbor’s trash, each type of tree, and all the birds and insects in it has a distinct odor profile telling your dog what it is, where it is, and which direction it’s moving in.

3. Dogs smell in stereo. The ability to smell separately - with each nostril - helps them determine from what direction smells come. A whole separate olfactory system, called the vomeronasal organ, above the roof of the mouth, detects the hormones all animals, including humans, naturally release.

For more on how dogs smell, check out the TED-Ed Lesson How do dogs “see” with their noses? - Alexandra Horowitz 


Animation by provinciastudio

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Photos: Bernard DUPONT

Jaguar male displays the classic Flehmen response. By curling back the lips in a grimace and exposing the roof of the mouth, pheromones in the air are transferred to the vomeronasal (Jacobson’s) organ located above the palate. This behavior is exhibited by many species of mammals, including cats, and functions as a way to “test” the chemical content in the urine (or feces) of the animal that left it behind.

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Headcanon: since Aligned Cybertronians have no noses, other structures fall to the task of being olfactory centers. For Starscream, and other Seekers of similar build, air is drawn inward through the sideburn-like vents on either side of their faceplate. 

There are initial sensors that determine smells right off the bat, but further inwards there is a sensory node not dissimilar to a reptilian Jacobson’s organ (vomeronasal organ) which allows Seekers to taste the air for chemical compounds. 

This was particularly useful before the War, when Seekers were actually assigned to seek out energon sources elsewhere. Now, their sense of smell is used to sniff out weaknesses of their opponents and also potential threats. 

However, this sense is not infallible, as there are multiple instances of where Starscream eschews the information gained from it in favor of his own blind ambition. 

Typical.

a tiny organ composed of two small pits a few centimeters inside the nasal passage called the vomeronasal organ, has the sole purpose of detecting trace amounts of airborne chemicals called “pheromones.”

specialized nerve pathways known as “Nerve O” lead from the VNO and run directly to the brain. these nerves become active with a flood of electrical impulses when subjected to specific human pheromones. these impulses are sent directly to the limbic region of the brain, also known as the “seat of emotions.” this region of the brain is not directly connected to reason or cognitive thought patterns, rather it controls our emotions and sexual desires.

when our sexual and romantic feelings overwhelm us, our brains release a chemical called phenethylamine which in turn kicks on dopamine production. this powerful cascade of events can happen in a matter of seconds, but the effects can last a life time.

and there’s nothing you can do about it.

Ideabird 8/3/12

The vomeronasal organ (VNO) is a secondary chemical reception organ (like smell) in many mammals, and possibly in humans. Unlike smell, it only registers chemical messages, pheremones, from your own species. There is much debate over whether adults still have them, or if they’re reabsorbed into the body as we age. In any case, the genes appear to be there, even if not expressed. The gene gets expressed, and we all suddenly have six senses. We learn not just to receive these pheremonic messages, but that we can communicate with them, creating something as beautiful and primal as music, but in a new sense.

Everything in the street, every passing person or car, any contents of the neighbor’s trash, each type of tree, and all the birds and insects in it has a distinct odor profile telling your dog what it is, where it is, and which direction it’s moving in. Besides being much more powerful than ours, a dog’s sense of smell can pick up things that can’t even be seen at all. A whole separate olfactory system, called the vomeronasal organ, above the roof of the mouth, detects the hormones all animals, including humans, naturally release.

From the TED-Ed Lesson How do dogs “see” with their noses? - Alexandra Horowitz

Animation by Provincia Studio