Thursday, March 27, 2014

Olfaction: Your Nose Knows

So we all know we have five senses; sight, hearing, taste smell and touch. I think we all know by now what we can do with each of this senses BUT would you be able to explain what or exactly how this senses work? Today we'll be discussing one of these senses in particular and that is, the sense of smell. Can you imagine what it would be like to go around in life without being able to smell the food you eat or not being able to be outside in a spring afternoon and smell the fresh scent of the flowers, trees, and grass? I mean there are some situations I think I could get by without smelling, but we won't be thinking of those today.

So the sense of smell is usually referred to as that, the sense of smell but today I'd like for you all to learn of a new term; olfaction. Olfaction, which is the sense of smell, is the response to chemicals that contact the membranes inside the nose. It plays an important role on our food selection and believe it or not in social behavior as well.

Of course the nose is the organ responsible for the sense of smell but have you ever wondered how it gets transmitted or signaled to our brain, so we can somehow know whether we like a smell or not? Take a look at the image below (I'm a visual learner so seeing videos and images explaining step by step of systems and procedures really help me understand them better, and I hope it does the same for you).

The neurons responsible for smell are the olfactory cells which are located in the (Cilia) nasal cavity, you can see them in the closer image of them below. As the image depicts once the odorant molecules are inhaled, they activate the olfactory receptor cells by binding to receptors, at the same time its axon carries an impulse to the olfactory bulb. The Olfactory bulb then sends axons to the olfactory area of the cerebral cortex, hypothalamus amygdala, and the hippocampus where a complex substance can activate a scattered population of cells.



As with anything else humans differentiate in olfaction. Here are some facts I found to be quite interesting:

  • Everyone has a unique "smell print". No two people smell the same way.
  • Scents can cue memories. As in when you smell a specific scent it might take you back to for example when you were a kid and your grandma baked for you.
  • Women tend to have stronger smell senses than men.
  • Dogs' olfactory ability is estimated to be 1,000 to 10,000 times better than humans.
  • About 5% of the population suffers of Anosmia; a disorder in which you can't smell.
  • A cockroach antenna has 195,000 olfactory receptors.

Want to test yourself on what you learned on today's blog? Go ahead and take the Olfaction Quiz! Let me know how you do on it!




http://faculty.washington.edu/chudler/nosek.html
http://compassionate-therapy.net.au/resources/the-senses-olfaction/

3 comments:

  1. Hey Maria, I for one can definitely not imagine not smelling anything ever again, as is the case for individuals with anosmia. I would definitely miss the smell of bread the most! I recently read an article that scientists at the Monell Center are working on possible treatments for anosmia using stem cells because of the ability of olfactory cells to regenerate throughout our lifetime; I certainly hope they uncover some interesting and helpful results.

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  2. I enjoyed reading your blog, I felt it was very informative on the subject of smell, I liked how you stated, " Olfaction, which is the sense of smell, is the response to chemicals that contact the membranes inside the nose. It plays an important role on our food selection and believe it or not in social behavior as well."

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  3. Hey Maria, I really enjoyed your reading your blog post. I had somewhat of an idea that dogs had a better sense of smell than us, but I never imagined that it was that much better. No wonder law enforcements use dogs to help them catch illegal substances. I had no idea that anosmia even existed. I could not imagine living without being able to smell food, flowers, or fragrances.

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