1. 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)

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

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

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

5. How are Taste and Smell Related?

6. 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!

7. Relationship of Taste and Smell (1m7s)

8. 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

9. Slim Goodbody: Olfactory Organs (1m 26s)

10. 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

11. 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

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

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

14. 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

16. The Chemistry of Smell (3m1s)

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

18. Olfactory Nerve Pathway Flow Map

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

20. Olfactory receptor:
Olfactory receptor stimulated
Generates nerve impulse!

21. Smell Receptors- Odors Magic School Bus (2m30s)

22. 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

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

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

25. 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

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

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

28. Smell Crash Course: A+P 6m18

29. 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)

30. 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).

31. 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