Tag: smell

Pheromones

Hola! To conclude our posts on aromatherapy and how smells work, I am going to break down pheromones for you. Hold tight, it might get a bit science-y.  Feel free to leave questions or comments at the end.

Last time, we briefly mentioned pheromones.  Here’s a refresher:

    In humans, our olfactory systems are rather elementary compared to other animals but it is still important for gathering information.  Odors and pheromones are translated into those electrical signals, conveying messages to the brain that elicit some type of response.  Odors are detected in the nose in the nasal olfactory epithelium (OE).  

    Animals detect pheromones via the VNO, the vomeronasal organ.  Some scientists believe that the VNO is an inactive organ in humans and that humans simply do not communicate via chemosignals.   Others know that scientific evidence proves this very concept.  Numerous tests have shown that when exposed to the smell of mens’ sweat, women’s physiological responses demonstrated statistically significant changes, classifying the sweat, or components of it, as pheromones.

 

So, what are pheromones?

Pheromones, like other hormones, are at the core, single compounds or small sets of chemicals secreted by animals.  Pheromones are set apart from other hormones in that once secreted, they act outside the body to affect the behavior of other animals, rather than just the animal secreting the pheromone.

There are several types of pheromones and each is secreted to trigger different types of behavior.  Pheromones are often misunderstood and considered to be related only to sex.  They are secreted for various other reasons:  alarm, bonding, food, marking territory, communicating that another animal should back off, etc.

Pheromones are detected by animals through an organ in the nose named the VNO (Vomeronasal Organ).  The VNO is connected to the brain via the hypothalamus.  This is how animals “receive” the communication.  Humans have the same 4 types of pheromones as other animals: releasers, primers, signalers, and modulators.  

  • Releaser pheromones are the ones most commonly thought to communicate sexual desire to another human, however there isn’t a lot of current evidence on the reliance of these pheromones in sexual attraction.  There is some evidence showing the involvement of releaser pheromones in guiding an infant to a lactating mother.
  • Primer pheromones are linked to the reproductive system.  They can impact puberty, menstruation, and pregnancy. This would include the lengthening, shortening, or synchronization of menstrual cycles based on who the menstruating woman was around, male or female, and how often.
  • Signaler pheromones are informative and communicate a certain type of information between humans. The most commonly cited example is the one of a mother being able to identify her newborn by scent alone.  Ovulating women may also signal when they are fertile.
  • Modulator pheromones communicate that a bodily function of another human needs to be altered in some way.  This can be anything from mood to sexual desire.

If you made it this far, thanks for hanging in there! You are now equipped with a whole lot of nerdy knowledge about smells work and why they matter.  Feel free to leave your comments below.

 

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How does the sense of smell work?

Welcome!  

Today we are going to learn how the sense of smell works.  If you are wondering why an aromatherapist would care, head over to my previous post for a quick primer. Don’t worry, I’ll wait.

Now, let’s get into some granularity and talk about how the sense of smell works.  This is one of those topics that really sets professionals apart and illustrates their training.

So how does the sense of smell work?

 In the interest of time I will simplify this quite a bit.  Molecules are inhaled through the nose (essential oils, perfumes, nasty odors, they are all molecules of something).  The information is carried via an odor molecule which is turned into an electrical signal in the sensory neurons.    Olfaction, the ability to smell, and translate odors to electrical signals, is pivotal to the animals’ ability to find food and locate mates.  

In humans, our olfactory systems are rather elementary compared to other animals but it is still important for gathering information.  Odors and pheromones are translated into those electrical signals, conveying messages to the brain that elicit some type of response.  Odors are detected in the nose in the nasal olfactory epithelium (OE).

Animals detect pheromones via the VNO, the vomeronasal organ.  Some scientists believe that the VNO is an inactive organ in humans and that humans simply do not communicate via chemosignals.   Others know that scientific evidence proves this very concept.  Numerous tests have shown that when exposed to the smell of mens’ sweat, women’s physiological responses demonstrated statistically significant changes, classifying the sweat, or components of it, as pheromones.

Okay so we smelled something, the molecule was absorbed by the mucous membranes in our noses and were translated into electrical signals that are sent to the brain.  Then what? The olfactory passageways sent information to the olfactory cortex, located at the base of the frontal lobe of the brain.  Yep, what you smell is translated into a signal that is sent right to your brain.  From there it can be routed all over your brain, into various areas with various functions. The key to remember is that the brain controls things such as emotions, pain, memories, and a lot of other things. This is why aromatherapy can have both physical and psychological impacts.  If you are really fascinated by the science, there are plenty of courses online.  For our purposes, you get the picture.

Given that an essential oil has the power to communicate messages to the brain and those messages may cause a physical, mental, or emotional response, can you see why it is so important for an aromatherapist to understand olfaction?

Interested in learning more? My next post will be all about pheromones.

 

References:

Sense of Smell Institute. (2009). Human Pheromones: What’s Purported, What’s Supported. [White paper].Retrieved from http://files.achs.edu/resource/aroma501/human_pheromones_final.pdf