Smelling

1. Smelling Tiffany Wang Anna Laurence Brit Sharon Aliza Heeren Timothy Chong

2. Introduction to smelling • Chemical sense • Humans can distinguish between thousands of different odors • 7 main categories of smell: • Camphoraceous, musky, floral, •         Pepperminty, ethereal, pungen,                                  putrid

3. Introduction to Smell Continued • Attraction of smell • Every person has a different smell • Opposites attract • Attraction between mother and child • Pheromone • Animals use smell for: • Marking territory  • Finding food • Finding a mate

4. Structure of olfactory system • At the top part of the nasal cavity • .8 to 1.5 square inch • From 10 million to 100 million smell receptors • Most smell comes from odoriferous molecules in inhaled air or through nasopharynx

6. Overview of the Science Behind Smell Signals from the olfactory tract are transmitted to the brain to the -olfactory cortex, -structures of the limbic system: hippocampus, amygdala, and hypothalamus.

7. The olfactory system is the only system that does not go through the thalamus, rather the signal goes straight to the temporallobe and the limbic system The limbic system is involved with emotional behavior and memory. This is why a certain smell often brings back memories associated with the object.

8. The In Depth Neuroscience Chemicals that act as stimuli, called odorants, interact with olfactory receptor neurons in the olfactory epithelium— a membranous sheet that lines the interior of the nose

9. The receptor neurons send signals to neurons in the Olfactory Bulb.  Those neurons then send the message to the pyriform cortex in the temporal lobe The receptor neurons also project to a the hypothalamus and amygdala.

10. How does this Happen? The Olfactory Epithalium has many terminals on it, Each one containing millions of sensory neurons On every terminal there are receptor sites which, when bound to an oderant, trigger an action potential The axon terminals of the olfactory sensory neurons are in the olfactory bulb, so the synapse that sends the message to the next neuron occurs there, in a structure called the Glomeruli

11. There are different types of olfactory sensory neurons. Certain stimuli have a stronger bond with each type. Each type ends its action potential in a different glomeruli From there, signals are relayed to various other parts of the brain.

13. A Visual Representation

14. Olfactory disorders • Cacosmia • Hyperosmia • Phantosmia • Anosmia • Dysosmia • Hyposmia • Euosmia =

15. Causes of olfactory disorders • Severe upper respiratory infection • Psychosis! • Inflamed mucous membrane • Tumor • Medication • Diseases • Head injury/brain damage • Hormonal disturbances  • Before migraines

16. Activity"Smell the Rainbow" 1. We will give everyone a cup full of skittles. 2. Partner up with the person sitting next to you. 3. Choose who will go first for the activity. 4. The partner #1 must close their eyes and pinch their nose shut. 5. The partner #2 will then choose a color skittle and give it partner #1 to eat.  6.  Partner #1 will be asked to identify what flavor skittle they just ate.  7. After 30 seconds partner #1 may unplug their nose and will again be asked to identify what flavor skittle they just ate. 8.  Partner #2 will then reveal the true flavor of the candy. 9. Switch roles.  Could you identify the true flavor of the candy? If so, when? Did your taste sensations change when you opened your nose?

17. Activity Explanation • With nose closed you are relying on the taste receptors on your tongue. •  Tongue can only perceive sweet or sour. Not enough to identify flavors. •  After sucking on candy for awhile olfactory receptors may come into play allowing you to identify the flavor.  •  Scent molecules from the candy travel into the nasal passages through a "back door" (passage at back of the throat).  • Molecules arrive at the olfactory bulb and are recognized by olfactory receptors, which identify the specific flavor of the molecule.  •  When you unplug your nose, the olfactory bulb can perform normally and it is easier to identify the flavor of the candy. 

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19. Bibliography (Continued)  Purves, D., and GJ Augustine, eds. Neuroscience. Ed. D. Fitzpatrick. 2nd ed. Bethesda: National Center for Biotechnology Information, 2001. The Organization of the Olfactory System. NCBI. Web. 22 Oct. 2011. <http://www.ncbi.nlm.nih.gov/books/NBK10982/>. Rayner, Claire, P. B. C. Fenwick, and John Reckless. The Rand McNally Atlas of the                         Body and Mind. New York: Rand McNally, 1976. Print. "Sense-sational Nutrition." MotherNature.com. Web. 23 Oct. 2011.                         <http://library.mothernature.com/l/preventions-healing-with-vitamins/taste-and                         smell-problems_1017.html>. "Smell Disorders." National Institute on Deafness and Other Communication Disorders                         [NIDCD]. July 2009. Web. 19 Oct. 2011.                         <http://www.nidcd.nih.gov/health/smelltaste/pages/smell.aspx>. "Smell and Taste." Psychology Basics. Ed. Frank N. Major, Jason. "Losing Sense of                         Smell May Predict Psychosis." The University of Melbourne | News. The                         University of Melbourne, 1 Dec. 2003. Web. 23 Oct. 2011.                         <http://uninews.unimelb.edu.au/news/1056/>. “Smell and Taste." Psychology Basics. Ed. Frank N. Magill. Vol. 2. Pasadena: Salem,                         1998. 553-57. Print. Turkington, Carol. "Smell, Sense of." Encyclopedia of Brain and Brain Disorders. 2nd                         ed. 2002. 288-89. Print. "What Causes Olfactory Hallucinations (phantosmia)?" Mayo Clinic. 27 Mar. 2010. Web.                         23 Oct. 2011. <http://www.mayoclinic.com/health/phantosmia/AN01684>.