1. Special Senses: Olfaction and Taste
Lab Exercise 26
Special Senses:
Olfaction and Taste

2. Objectives Olfactory epithelium Taste receptors Taste sensation
Location
Cellular composition
Taste receptors
Structure, function
Location on tongue
Taste sensation
4 basic qualities
Chemical substances that elicit them

3. What is Olfaction? SMELL
Olfactory Epithelium (smell organ)
Covers inferior surface of cribriform plate,
superior perpendicular plate, &
superior nasal conchae
Fig. 17-1

4. Cellular Composition Olfactory epithelium:
Olfactory receptor cells (ciliated)
Supporting cells
Basal (stem) cells
Olfactory nerve fibers
Fig. 17-1

5. Sense of Taste
Dorsal tongue’s surface covered with papillae (small projections)—3 types
Taste buds (receptors) primarily on sides of ones at posterior tongue (“V”) and small ones all over mid-tongue
Fig. 17-2

6. Taste Buds (Receptors)
2 types of cells (epithelial)
Gustatory (taste) cells—receptor cells, w/ microvilli
Supporting cells
Fig. 17-2

7. Taste Buds (Receptors)
Nerve fibers enter each taste bud, to each taste cell
Certain chemicals detected by microvilli “activate” the taste cell
Fig. 17-2

8. 4 Primary Taste Sensations
Sour
Acids
Bitter
Quinine, PTC
Salty
Salt, NaCl
Sweet
Sugars, saccharin, amino acids

9. Plotting Taste?
“No differences in the structure of the taste buds, and taste buds in all portions of the tongue provide all 4 primary taste sensations.”
--Text, Martini
“A single taste bud contains 50–100 taste cells representing all 5 taste sensations (so the classic textbook pictures showing separate taste areas on the tongue are wrong).” --