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Olfaction retronasal

Stearic acid was successfully delivered to the human oral cavity by emulsions at 67-69 °C where this stimulus is in liquid form [4, 22]. Detection thresholds were identified by orthonasal olfaction, retronasal olfaction, gustation, and a multimodal presentation where the lipid emulsion was placed in the oral cavity in the absence of nose clips [4]. Although measured at different temperatures, intensity responses for stearic acid were similar to the 18-carbon cis- unsaturated fatty acids linoleic and oleic acid. Oral detection thresholds for stearic acid in the human oral cavity with emulsions, yielded thresholds near 0.032% (w/v) [4, 22]. In addition, most study participants were able to detect stearic acid in the oral cavity [4,22]. [Pg.10]

The sense of smell in humans is not limited to detection of those volatile molecules inhaled through the nose, termed orthonasal olfaction. Molecules released at the back of the mouth, particularly in the chewing of food, can make their way up through the nasopharynx to the olfactory epithelium, termed retronasal olfaction. This system is activated when air is exhaled. Orthonasal olfaction is used to detect the scent of flowers and perfumes, food aromas, the presence of skunks, and the like. Retronasal olfaction detects the volatile molecules released from food. It is retronasal olfaction that makes a major olfactory contribution to the taste of food. And it is retronasal olfaction that helped to elicit Proust s profound reaction to a madeleine dipped in tea. [Pg.355]

Eor a thoughtful analysis of orthonasal and retronasal olfaction, see G. M. Shepherd, Nature316-321 (2006). [Pg.385]

Coppola, D. M. and Coltrane, J. A. (1994). Retronasal or internasal olfaction can mediate odor-guided behaviors in newborn mice. Physiology and Behavior 56,729-736. [Pg.448]

Fig. 8E.2 Schematic drawing showing the compositional differences between the extract obtained by a total extraction technique and the vapor phases reaching the pituitary during ortho or retronasal olfaction. The extract is enriched in polar volatiles that cannot reach the pituitary either by ortho or retronasal pathways... Fig. 8E.2 Schematic drawing showing the compositional differences between the extract obtained by a total extraction technique and the vapor phases reaching the pituitary during ortho or retronasal olfaction. The extract is enriched in polar volatiles that cannot reach the pituitary either by ortho or retronasal pathways...
Quality testing of aromas is often only done by smell (olfaction) alone, i.e. through the nose. This is a serious error. Because it can be seen clearly from the above that an aroma needs to be taken into the mouth, simply because of the different, retronasal olfactory effect. For example, the different temperature in the mouth means that the active components producing the smell are carried past the olfactory epithelium retronasally and therefore differently. [Pg.578]

When Are Oral Cavity Odorants Available for Retronasal Olfaction ... [Pg.51]

The human oral cavity is potentially coimected to the nasal cavity by way of the buccopharynx (oropharynx), pharynx, and nasopharynx [1,2]. Under those circumstances in which this potential connection is open, the air movement of an exhalation that exits from the anterior nates (nostrils) can acquire odorants from the oral cavity and move them through the nasal cavity. If these odorants, while in the nasal cavity, reach the olfactory mucosa at a flow rate and concentration [3,4] that allow penetration to olfactory receptor neurons [5] and activation of these receptors such that sufficient central nervous system (CNS) responses develop, retronasal olfaction may occur. A limitation to the present understanding of retronasal olfaction is the absence of empirical or numerical models of retronasal odorant transport in adult humans. Such models have been published for orthonasal olfaction via the anterior nares [4,6] but are not presently available for retronasal olfaction (experimental airflow and odorant uptake analysis is in progress PW Scherer, personal communication, October 2002). [Pg.51]

Access from the oral cavity to the nasal cavity is necessary for retronasal olfaction, but it is not sufficient. As suggested, it is conceivable that odorants could reach the nasal cavity from the mouth but not arrive at the olfactory epithelium at all, or at least not in a quantity per unit time that would be sufficient to partition into the mucous covering of that sensory epithelium, activate relevant populations of olfactory receptor neurons, and... [Pg.51]

Several eore questions emerge When is the potential coimeetion between the human oral and nasal eavities open, and when is it closed Can odorants known to be present in the human oral cavity be detected by physical means in the nasal cavity, and, if so, under what circumstances As a measure of overall function of retronasal olfaction, with what accuracy can human observers identify odorants originating in the oral cavity ... [Pg.52]


See other pages where Olfaction retronasal is mentioned: [Pg.399]    [Pg.33]    [Pg.399]    [Pg.401]    [Pg.401]    [Pg.9]    [Pg.53]    [Pg.55]    [Pg.56]    [Pg.57]    [Pg.58]    [Pg.59]    [Pg.61]    [Pg.61]    [Pg.63]   
See also in sourсe #XX -- [ Pg.355 ]




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