1. Bio 449 Lecture 10 - Sensory Physiology II Sep. 17, 2010
General mechanisms (cont’d) Receptive field size Lateral inhibition Chemoreception - taste and smell Gustation Olfaction
Terms to Know Receptive field size Lateral inhibition Gustation Taste bud Taste receptor cell Umami Gustducin Tastant Olfaction Olfactory receptor cell Olfactory epithelium Olfactory bulb Odorant
Readings
Lectures 10 & 11: Chapter 10, pages
Lectures 12-14: Chapters 6 & 7

2. Receptive Field Size Fig. 10-3 (a) (b)
Compass with points separated by 20 mm
Skin surface
Skin surface
Primary sensory neurons
Secondary sensory neurons
One signal goes to the brain.
Two signals go to the brain.
Fig. 10-3

3. Gustation Fig. 10-16 Taste Bud Taste pore Sweet Umami Bitter
Salty or sour
Tight junction
Support cell
Receptor cells
Primary gustatory neurons
Serotonin
Presynaptic cell
ATP
Fig

4. Primary gustatory neurons
Taste Transduction 5 4 3 2 1
Sweet, umami, or bitter ligand
Gustducin
GPCR
Signal transduction
Primary gustatory neurons
Serotonin
Ca2+ ?
ATP
Salt
Sour
Cell depolarizes
Na+ H+
Fig

5. Receptor A
Receptor B
Receptor C
Receptor D

6. Olfaction Olfactory bulb Olfactory tract Olfactory epithelium
Fig

7. Olfaction Brain To limbic system and cerebral cortex Mitral cells
Olfactory receptors
Cilia
Glomeruli
Olfactory bulb
Bone
Olfaction

8. Olfactory Receptors Fig. 10-14 Developing olfactory cell
Olfactory receptor cell
Supporting cell
Olfactory cilia
Mucus layer
Fig

9. Touch Receptors Fig. 10-11 Hair Hair root Merkel receptors
Meissner’s corpuscle
Sensory nerves
Ruffini corpuscle
Pacinian corpuscle
Free nerve ending
Fig