Sponge: Set up Cornell Notes on pg. 47

Topic: 12. 3: Sense of Smell

Essential Question:1.Where are the olfactory receptors located?

2.Create your own example of sensory adaptation in regards to smell.

2.1 Atoms, Ions, and Molecules

12.3 : Sense of Smell

Tape:42- Receptor Lab 3044- HW: Diagnosing and Managing Pain Reading (Read/Highlight/?s)

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Sensory Adaptation

• What does it mean to “adapt” to something?

•Sensory adaptation is the ability to ignore unimportant stimuli or “get used” to

•Why is this important???•If you don’t ignore it, you would be overwhelmed by unimportant information

•Involves a decreased response to a particular stimulus from the receptors

•Sensory impulses become less frequent and may cease•Stronger stimulus is required to trigger impulses

Pg. 44

Ex: you are probably unaware of the pressure of your clothing on your skin until it is brought to your attention

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Video Notes

Olfactory Organs PicturePg.46

• Relationship of Taste and Smell• Slim Goodbody: Olfactory Organs• The Chemistry of Smell

• 2-5 bullets each!!!

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REVIEW: Special Senses

• Location of special senses?

•sensory receptors are within large, complex sensory organs in the head

• smell in olfactory organs------>olfactory receptors

• taste in taste buds-----> Taste cells (gustatory cells)

• hearing and equilibrium in ears------>hair cells

• sight in eyes----->Rods and cones

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Sense of SmellOlfactory Receptors

•chemoreceptors- respond to chemicals dissolved in liquids Similar to taste

• Function together and aid in food selection• 75-80% of flavor is actually the sense of smell!

Relationship of Taste and Smell (1m7s)

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Olfactory OrgansContain: 1. Olfactory receptors2. 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)

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• 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

11Please draw this picture on the top ½ of pg 46

*Olfactory Receptor cells

Brain

Ethmoid bone

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How are Taste and Smell Related?

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Olfactory Stimulation• 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

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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

The Chemistry of Smell (3m1s)

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Sponge: Set up Cornell Notes on pg. 49

Topic:

12. 3 Smell- Olfactory Nerve Pathways

Essential Question:1. Using your Nerve Pathways Flow Map, please write a “Smelly Story”. This story could be about any odor, good or bad.

2.1 Atoms, Ions, and Molecules

12. 3 Smell- Olfactory Nerve Pathways

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Olfactory Nerve Pathways• Once olfactory receptors are stimulated, nerve impulses

travel through…olfactory nerves olfactory bulbs olfactory tracts

limbic system and olfactory cortex

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Set up this flow map on pg. 49

Olfactory Nerve Pathways

Odorant Olfactory Olfactory Olfactory Limbic Olfactory Molecules Nerves Bulbs Tracts System Cortex

picture

picture

picture

picture

picture

picture

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Odorant Molecules

•Enter nasal cavity as gases•Dissolve partially in watery fluids that surround the cilia•Bond to receptor proteins on cilia•Stimulate olfactory receptors•Generate nerve impulse!

Smell Receptors- OdorsMagic School Bus (2m30s)

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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

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

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

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Limbic System•Brain center for memory and emotion

•Scents bring back memories

Spilled baby powder---------> Reminds you of your child as a baby

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

Essential Oils in the E.R. (3m11s)

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EQ: Your “Smelly Story”• Using your flow map, create a “story” based

on a smell you encounter.

– Remember to include a description for EACH part.• Odorant molecules• Olfactory Nerves • Olfactory Bulbs• Olfactory tracts• Limbic System • Olfactory Cortex

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Pg. 48

The Memory of my Father• As I pass a man walking down the street, I inhale a

pleasant odor in the air (Odorant molecules).

• 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 these impulses 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).

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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

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