Sponge: Set up Cornell Notes on pg. 47 Topic: 12. 4: Sense of Smell Essential Question: Where are the olfactory receptors located? Create your own example of sensory adaptation in regards to smell. (p. 43) 12.4 : Sense of Smell 2.1 Atoms, Ions, and Molecules Where are the olfactory receptors located? Create your own example of sensory adaptation in regards to smell. (p. 43)

Olfactory Organs Picture Pg.46 Video Notes 2-5 bullets each video (x 7 videos)!!!

REVIEW: Special Senses Location of special senses? Sensory receptors are within large, complex sensory organs in the head Smell in olfactory organs------>olfactory receptors

Sense of Smell Olfactory Receptors- Chemoreceptors- respond to chemicals dissolved in liquids. Similar to taste

How are Taste and Smell Related?

Sense of Smell Olfactory Receptors- Smell and taste function together and aid in food selection 75-80% of flavor is actually the sense of smell!

Relationship of Taste and Smell (1m7s)

Olfactory Organs Contain: Olfactory receptors Supporting epithelial cells covered with hair-like cilia Only nerve cells in direct contact with the outside environment Subject to damage The only neurons regularly replaced

Slim Goodbody: Olfactory Organs (1m 26s)

Olfactory Code Leading hypothesis- Each odor likely stimulates a distinct set of receptor cells The brain then recognizes the particular combination as an olfactory code or particular smell

Where do you think the olfactory organs are located? Olfactory organs located high in the nasal cavity above the usual pathway of inhaled air Sniffing and forcing air over receptor areas may be necessary to smell a faint odor

Please draw this picture on the top ½ of pg 46 Brain *Olfactory Receptor cells Ethmoid bone

Sensory Adaptation How long do you think sensory adaptation occurs for the sense of smell?

Sensory Adaptation Olfactory receptors undergo sensory adaptation RAPIDLY Sense of smell drops by 50% within a second after stimulation Within a minute the receptors may become insensitive to a given odor

The Chemistry of Smell (3m1s)

Olfactory Nerve Pathways Once olfactory receptors are stimulated, nerve impulses travel through… Olfactory receptors olfactory nerves olfactory bulbs olfactory tracts limbic system olfactory cortex

Olfactory Nerve Pathway Flow Map

Odorant Molecules Enter nasal cavity as gases Dissolve partially in watery fluids that surround the cilia Bond to receptor proteins on cilia

Olfactory receptor: Olfactory receptor stimulated Generates nerve impulse!

Smell Receptors- Odors Magic School Bus (2m30s)

Olfactory Nerves Contain sensory neurons located in the lining of the upper nasal cavity Translate the chemical signal into the electrochemical language of the nervous system

Olfactory Bulbs Extensions of cerebral cortex (brain) Sensory impulses are analyzed and sent along to olfactory tracts

Olfactory Tracts Impulses travel along these tracts to cerebral centers of the brain (passageway)

Spilled baby powder---------> Reminds you of your child as a baby Limbic System Brain center for memory and emotion Scents bring back memories Spilled baby powder---------> Reminds you of your child as a baby

Olfactory Cortex Located deep in the temporal lobes Interpret the impulses You recognize the smell!

Essential Oils in the E.R. (3m11s) https://www.youtube.com/watch?v=O1_1A3gRhpw

Smell Crash Course: A+P 6m18 https://www.youtube.com/watch?v=mFm3yA1nslE

My “smelly story” Pg. 47 Using your flow map, create a “story” based on a smell encounter. Remember to include a description for EACH part. Odorant molecules (initial odor) Olfactory Nerves (spark nerve impulse) Olfactory Bulbs/Olfactory tracts (interpret and send) Limbic System (emotion) Olfactory Cortex (recognition)

Ex: The Memory of my Father As I pass a man walking down the street, I inhale a pleasant odor in the air (Odorant molecules). The scent sparks a nerve impulse in my nose. In an instant, my olfactory nerves translate this scent into a chemical signal that my nervous system can understand. My olfactory bulbs analyze these sensory impulses and are sent along my olfactory tract to my brain. As the signals pass through my limbic system, I am reminded of memories of my father and I feel happy. I realize that the man I just passed was wearing the same type of cologne that my father always wore when I was a child. (Olfactory cortex).

Let’s Share the Smelliest Story! Table Share: EVERY person must read their “Smelly Story” Choose a story that best demonstrates the olfactory nerve pathways Class share: Each table will share their favorite story The person reading the “Smelly Story” to the class does not need to be the person who wrote it