Deck 14: Olfaction: Perceiving Odors

Question 1

The olfactory receptor neurons are embedded in the:

A) pharynx.
B) olfactory epithelium.
C) cribriform plate.
D) olfactory bulb.

Answer 1

B

Question 2

The relationship between age and olfactory-identification ability, as measured by the University of Pennsylvania Smell Identification Test (UPSIT) indicated that:

A) males and females perform about the same.
B) males score higher than females do.
C) females score higher than males do.
D) males perform better than females do up to the sixth decade of life.

Answer 2

C

Question 3

Axons of mitral and tufted cells form the:

A) olfactory tract.
B) olfactory nerve.
C) turbinates.
D) olfactory bulb.

Answer 3

A

Question 4

Which statement is TRUE of odorants?

A) They always evoke a response regardless of their concentration.
B) All species of animals detect the same odorants.
C) A single substance, such as a rose, will emit many different odorants.
D) Odorant molecules with similar structures always smell the same.

Question 5

Studies by Bende and Nordin (1997) suggested that:

A) the olfactory expertise of professional wine tasters is domain specific.
B) novices are better at discriminating, remembering and identifying wine-related odors.
C) nonprefessional wine tasters are better at detecting odors than the experts.
D) professional wine tasters are better than nonprofessionals at identifying and discriminating the odors of substances other than wine.

Question 6

When a person has reduced sensitivity to odorants that are chemically similar to odorants to which the person has been repeatedly exposed, the phenomenon is called:

A) adaptation.
B) cross-adaptation.
C) assimilation.
D) accommodation.

Question 7

Mitral cells and tufted cells synapse with the olfactory receptor neurons in the:

A) pharynx.
B) oral cavity.
C) cribriform plate.
D) glomeruli.

Question 8

Turbinates are:

A) olfactory receptors.
B) odorant molecules.
C) neurons that transduce odorant molecules into neural signals.
D) bony convolutions of tissue.

Question 9

Based on the use of contextual information, when dining out at a restaurant, which odor would be the EASIEST to identify?

A) coffee
B) soap
C) roses
D) perfume

Question 10

The function of the turbinates is to:

A) keep the nasal passages free from mucus.
B) keep odor molecules from escaping through the pharynx.
C) disperse the air evenly throughout each nasal cavity.
D) transduce odor molecules into neural signals.

Question 11

Which statement is TRUE of the relationship between olfaction and cigarette smoking?

A) The ability to identify odors decreases with the number of years spent smoking.
B) A smoker's ability to identify odors is worse compared to nonsmokers, but it is not impacted by the number of years the person has smoked.
C) Smoking does not impact the ability to identify odors.
D) Smoking permanently damages a person's ability to identify odors.

Question 12

Which odorant has the LOWEST detection threshold?

A) vanillin
B) chlorine
C) acetone
D) menthol

Question 13

In olfaction, _____ is the phenomenon of reduced sensitivity to odorants to which a person has been continually or repeatedly exposed.

A) adaptation
B) cross-adaptation
C) assimilation
D) accommodation

Question 14

A _____ consists of two or more atoms bound together by electromagnetic forces.

A) nucleus
B) molecule
C) neuron
D) receptor

Question 15

Valencia is applying perfume for her date with James. A few minutes later, she wonders if she has applied enough but decides not to apply any more. Is this a wise decision?

A) It is wise because she knows that she has adapted to the smell of her perfume, and if she adds more, it would be too strong for others.
B) It is not wise because cross-adaptation research says others likely won't be able to smell it because it will blend in with other similar odors in the room.
C) It is wise because cross-adaptation research shows that others will be able to continue detecting it very easily.
D) It is not wise because the smell of the perfume has become weak in intensity. Therefore, others are not likely to smell it.

Question 16

Humans have approximately _____ different types of olfactory receptor neurons.

A) 1 billion
B) 3-7 million
C) 350
D) 2,000-3,000

Question 17

The small spherical structures in the olfactory bulb are called:

A) glomeruli.
B) tufted cells.
C) mitral cells.
D) olfactory receptors.

Question 18

The relationship between age and olfactory impairment indicates that, across the life span:

A) men and women perform about the same.
B) women perform better than men do.
C) men perform better than women do.
D) men perform better as they age, while women perform poorly as they age.

Question 19

Which statement is NOT true of acquired anosmia?

A) The ability to smell odors is lost.
B) The ability to taste flavors is diminished.
C) Mood changes, such as depression, can occur.
D) This condition is irreversible.

Question 20

Which scenario will most likely result in the HIGHEST concentration of odorant molecules?

A) Chen opens the refrigerator to find the fish from last night's dinner rotting away.
B) Roberto, the neighbor next door, is grilling chicken in his backyard.
C) Aida spills a drop of perfume on her balcony.
D) A skunk sprays a dog that lives two blocks away from Imamu's home.

Question 21

Research has shown that the orbitofrontal cortex (OFC) is involved in:

A) perceptually identifying specific odors.
B) representing the emotional dimensions of odor perception.
C) perceptually identifying general categories of odors.
D) producing representations of the quality of an odor.

Question 22

Willander and Larsson (2006) studied autobiographical memories elicited by odors, words, or pictures for participants 65 to 80 years of age. They found that for the group that:

A) saw words or pictures describing the odors, the greatest percentage of evoked memories came from the most recent decade of life.
B) saw words or pictures describing the odors, the greatest percentage of evoked memories came from the first decade of life.
C) smelled odors, the greatest percentage of evoked memories came from the most recent decade of life.
D) smelled odors, the greatest percentage of evoked memories came from the first decade of life.

Question 23

Stevenson et al. (2010) studied human responses to fecal and urinous odorants and found that:

A) participants, regardless of age, tended to respond with facial expressions of disgust.
B) only adult participants tended to respond with facial expressions of disgust.
C) all participants under the age of 5 responded with facial expressions of disgust.
D) children with no obvious disgust reactions were those of parents with the most obvious disgust reactions.

Question 24

The fact that there are many more types of olfactory receptor neurons than types of color cones in vision indicates that:

A) each ORN can respond to only one specific odorant.
B) olfactory receptor neurons can be more narrowly tuned than cones.
C) olfactory receptor neurons can be more broadly tuned than cones.
D) the neural codes for odors and colors cannot be meaningfully compared.

Question 25

The fact that odor-evoked memories that tend to be quickly acquired, long lasting, and emotionally charged has been attributed to the fact that the olfactory pathway includes the amygdala, the orbitofrontal cortex, and the:

A) larynx.
B) thalamus.
C) pharynx.
D) hippocampus.

Question 26

The _____ cortex is the primary olfactory cortex.

A) entorhinal
B) anterior insular
C) piriform
D) orbitofrontal

Question 27

Which subdivision of the piriform cortex produces representations of the features of odorant molecules?

A) anterior
B) posterior
C) lateral
D) medial

Question 28

The piriform cortex is considered to be the _____ olfactory cortex.

A) primary
B) secondary
C) auxiliary
D) tertiary

Question 29

According to the research of Rabin and Cain (1984), the ability to acquire long-lasting memories for odors revealed that:

A) memory for odors tended to fade very little when tested from 10 minutes to 7 days later.
B) memory for odors tended to fade considerably when tested from 10 minutes to 7 days later.
C) memory for those odors that could not be easily named tended to fade less than memory for those odors that could be easily named.
D) memory for only those odors that could be easily named tended to fade considerably when tested from 10 minutes to 7 days later.

Question 30

The area of the brain that receives inputs from the piriform cortex and is involved in evaluating the pleasantness of stimuli is the:

A) hypothalamus.
B) amygdala.
C) hippocampus.
D) orbitofrontal cortex.

Question 31

Cindy inhales a complex mixture of odorants that she recognizes and identifies as bacon. Which area of the piriform cortex is responsible for her ability to name the odor?

A) anterior
B) posterior
C) lateral
D) medial

Question 32

The entorhinal cortex is the gateway to the _____, where long-term memories are stored and retrieved.

A) piriform cortex
B) amygdala
C) hippocampus
D) hypothalamus

Question 33

The results of the study on neural coding for odors by Malnic et al. (1999) indicated that:

A) each different odorant stimulated only one olfactory receptor neuron.
B) a particular olfactory receptor neuron responded to only one chemical family of odorants.
C) the pattern of olfactory receptor neuron responses determines how an odorant smells.
D) the pattern of olfactory receptor neuron responses did not differ enough across odorants to account for differences in how odorants smelled.

Question 34

Howard et al. (2009) used fMRI to measure the activity in the orbitofrontal cortex (OFC) in response to odorants with either minty, woody, or citrus qualities, and the results showed that the activity in the OFC:

A) was greatest for minty and least for woody odors.
B) differed significantly for the three different odors.
C) did not reflect differences in the quality of the three odors.
D) represented the identity of odors.

Question 35

Dogs are more sensitive at detecting odors than humans because:

A) dogs have more types of receptors but the same overall number of receptors.
B) both have the same number of receptors. However, more sophisticated processing occurs at the cortical level in dogs.
C) dogs have fewer types of receptors, so they become less confused between smells.
D) dogs have as many as 1 billion receptors, while humans have only 3-7 million.

Question 36

The only sensory system in which the pathway from the receptors to the cortex does NOT go through the thalamus is the _____ system.

A) olfactory
B) visual
C) somatosensory
D) auditory

Question 37

The _____ is the only brain region that both receives signals directly from the olfactory bulb and is known to be dedicated solely to olfaction.

A) entorhinal cortex
B) amygdala
C) piriform cortex
D) hypothalamus

Question 38

Willander and Larsson (2006) studied autobiographical memories elicited by odors, words, or pictures for participants aged 65 to 80 years. They found that the feeling of being "brought back in time" was STRONGEST for participants in the _____ age group.

A) words
B) pictures
C) odors
D) words and pictures

Question 39

Which subdivision of the piriform cortex represents the quality of an odor, regardless of whether the odor is simple or complex?

A) anterior
B) posterior
C) lateral
D) medial

Question 40

The olfactory pathway from the receptors to the cortex does NOT go through the thalamus. This suggests that the:

A) olfactory system evolved earlier than the other sensory systems did.
B) olfactory system evolved later than the other sensory systems did.
C) olfactory pathway came into existence after the thalamus developed.
D) the other sensory systems coevolved with the olfactory system.

Question 41

In many species, chemicals that would seem to qualify as pheromones are sensed via a _____ system.

A) vestibular
B) somatosensory
C) vomeronasal olfactory
D) auditory

Question 42

Zhou and Chen's (2008) fMRI study recorded the brain responses of women when exposed to the smell of male sweat (obtained from watching either neutral or erotic videos) and a steroid derived from male hormones. The results reported:

A) that women knew the difference between the sweat and the steroid.
B) an increase in brain activity for the sexual sweat condition.
C) an increase in brain activity for the steroid but not for the sweat condition.
D) that women perceived the sexual sweat as being especially pleasant or intense.

Question 43

Since the olfactory pathway includes the amygdala, orbitofrontal cortex, and the hippocampus, odor-evoked memories tend to be:

A) quickly acquired.
B) slowly acquired and short lived.
C) slowly acquired, emotionally neutral, and short lived.
D) quickly acquired, long lasting, and emotionally charged.

Question 44

Murray is waiting in a bagel shop for his friend Ben. The air in the shop is filled with the aroma of freshly baked sesame, garlic, and cinnamon-raisin bagels. Ben arrives 10 minutes later, just as a fresh batch of onion bagels were coming out of the oven. Explain whether Murray or Ben will be able to detect the odor of the onion bagels more easily.

Question 45

Explain the various factors involved in identifying and discriminating odors.

Question 46

Describe the effects of three different causes of olfactory impairments. Explain how olfactory performance is recovered in these cases (if possible).

Question 47

What is meant by population coding for an odorant?

Question 48

What is odor adaptation and cross-adaptation? Provide an example of each from your life.

Question 49

_____ are chemicals emitted by organisms that evoke behavioral and hormonal responses in other individuals of the same species.

A) Endorphins
B) Neurotransmitters
C) Pheromones
D) Narcotics

Question 50

The vomeronasal olfactory system in many species:

A) is another name for the main olfactory system.
B) is the system for detecting pheromones.
C) includes the piriform cortex in its pathway.
D) does not include the amygdala in its pathway.

Question 51

Which statement is NOT true about the eNose?

A) It contains only a few dozen types of sensors compared with the 350 receptors found in the human nose.
B) Each sensor can respond to a range of substances.
C) Each odorant results in a unique pattern of responses that can be used to identify the molecule.
D) It does not respond to the same molecules to which the human nose responds.

Question 52

Caio's olfactory sense picked up the smell of a particular food dish that he had not eaten recently. The smell caused him to remember events from the past. According to the studies on autobiographical memories, which decade of his life is Caio MOST likely to remember? Explain why.

Question 53

Which area in the brain is responsible for odor-evoked memories to be quickly acquired and become long lasting?

A) the hippocampus
B) the thalamus
C) the piriform cortex
D) the hypothalamus

Question 54

The women on a soccer team find that by the end of the soccer season their menstrual cycles have become more synchronized. Explain how odor detection and pheromones could account for this finding.

Question 55

In a study conducted by Miller and Maner (2010), male college students smelled T-shirts that had been worn under different conditions by four women as they slept. Some of the T-shirts had been worn by the women on the nights closest to ovulation, some on the nights farthest from ovulation, and some had never been worn. When the testosterone levels of the men were measured in the saliva samples:

A) there were no differences in testosterone levels across the different conditions.
B) the highest levels occurred after the men had smelled the T-shirts of the ovulating women.
C) the highest levels occurred after the men had smelled the T-shirts of the women who were not ovulating.
D) the highest levels occurred after the men had smelled the unworn T-shirts.

Question 56

Miller and Maner (2010) had male college students smell T-shirts worn by women as they slept. Some of the T-shirts had been worn by the women on the nights closest to ovulation, some on the nights farthest from ovulation, and some had never been worn. The men were asked to rate the pleasantness of the odors of the T-shirts. The results showed that there were:

A) no differences in pleasantness ratings across the different T-shirt conditions.
B) differences in pleasantness ratings, with the highest ratings for the T-shirts of the ovulating women.
C) differences in pleasantness ratings, with the highest ratings for the T-shirts of the females who were not ovulating.
D) differences in pleasantness ratings, with the lowest ratings for the unworn T-shirts.

Question 57

Amanda smells the shirts of six different men whom she has never met. According to the research by Jacob et al. (2002) on the role of Human Leukocyte antigen (HLA) genes responsible for regulating the immune system in offspring, Amanda will prefer the shirts of men who have HLA genes that are:

A) very different from her own.
B) the closest match to her own.
C) preferred by the majority of other women.
D) rated as strongest in concentration.

Question 58

Define detection threshold. Describe the typical procedure used to measure the detection threshold of an odor.

Question 59

If an organism only had three types of olfactory receptor neurons (ORNs), how many different odorants could be encoded? (Assume each ORN can have only one level of activation; it is either active or inactive.)

Question 60

How would a person's sense of smell be affected if these brain regions were damaged: the olfactory bulb, the posterior piriform cortex, and the orbitofrontal cortex?