Chapter 14 Flashcards
what is orthonasal olfaction?
perceiving odors through the nostrils
what is retronasal olfaction?
perceiving odors through the mouth while breathing/chewing
what are the molecular properties of odorants?
volatile and hydrophobic
what does retronasal olfaction give us?
the experience of flavor
what is the olfactory epithelium?
the “retina” of the nose
what do sustentacular cells/supporting cells do?
maintain metabolic and physical support
what are basal cells/stem cells do?
they are precursor cells to olfactory sensory neurons
what are olfactory sensory neurons?
receptors for odorant molecules
how does a hard blow to the head cause anosmia?
a hard blow can fracture the cribriform plate, slicing axons
what animals are super smellers?
pigs and elephants
how are dogs better at smelling than humans?
they have 100x more olfactory sensory neurons
what is the order process of smelling?
olfactory nerves, olfactory bulb, primary olfactory cortex
what is the orbitofrontal cortex for?
determines pleasure/displeasure in food; secondary olfactory cortex
what is included in the limbic system?
primary olfactory cortex, amygdala, hippocampus, entorhinal cortex
what is the entorhinal cortex for?
emotion and memory
what are pseudogenes?
non-functional genes
what does the number of copies of a gene have to do with sensitivity?
the more copies = the more sensitive
what does the trigeminal nerve do?
gives the “feel” of an odorant; responds to stimuli around the mouth, nose, eyes
what is the shape-pattern theory?
odorant molecules and olfactory receptors have different shapes, and the detection of an odorant depends on how well the shapes fit together
what is binaral rivalry?
competition between the two nostrils for odor perception
what does synthesis mean?
we smell mixtures of odorants
what does analytical mean?
we smell one scent at a time
what is the tip-of-the-nose phenomenon?
inability to name an odor even though it is familiar
what is the correct order of the psychophysical methods in studying olfaction?
detection, discrimination, recognition
how do you measure detection?
the staircase method
how do you measure discrimination?
the triangle test
how do you measure recognition?
labeling with the correct identification of the odor
do women or men have a better sense of smell?
women
what happens with odor sensation with age?
it declines; odor receptors die off and few regenerate
what is receptor adaptation?
continual exposure to an odorant leads to a decrease in detection
what is cross-adaptation?
a reduction in detection of one odorant after exposure to a different odorant
what is cognitive habituation?
after long-term exposure, you are unable to detect the same odor
what does odor hedonics mean?
the likeness level of an odor
what is the vomeronasal organ?
chemical-sensing organ for pheromones
what are pheromones?
a chemical emitted by one animal that triggers a physiological/behavioral response in another member of the same species
what do primer pheromones do?
change hormones
what do releaser pheromones do?
change behavior
what are chemosignals?
various chemicals emitted by humans that change mood, behavior, hormones, sexual arousal
what is taste?
sensations caused by contact to receptors on the tongue and roof of the mouth
what is flavor?
produced by retronasal olfaction
what is retronasal olfaction?
gives the experience of flavor by perceiving odors through the mouth while breathing or chewing
what is the chorda tympani?
carries information from taste receptors to the brain
what is the foliate papillae?
contains taste buds on sides of tongue in the back
what is the filiform papillae?
no taste function; for “grooming” in cats
what is the fungiform papillae?
contains taste buds; supertasters have more; mushroom shaped
what is the circumvallate papillae?
contains taste buds; inverted V, circular shaped
why is the tongue map a myth?
doesn’t predict real-world taste sensitivities/intensities; there is very little variation in taste thresholds
what is the gustatory cortex?
insular cortex
what are the 4 basic tastes?
sweet, salty, bitter, sour
what is the purpose of salty?
maintains nerve and muscle functions; loss of it leads to death
what is the purpose of sour?
for likeness; high concentration will damage internal and external body tissues
what is the purpose of bitter?
protects plants from predators; signals toxicity; protects from cancer
what is the purpose of sweet?
source of energy
what is salt and sour made from?
ions
what is bitter and sweet made from?
proteins
why is umami not considered a basic taste?
protein molecules are too large to stimulate taste or olfaction
why is fat not considered a basic taste?
fat is sensed on the digestive tract, not the mouth
what alleles are nontasters born with?
2 recessive alleles
what alleles are tasters born with?
1 or 2 dominant alleles
what taste are supertasters sensitve to?
bitter; they eat less greens
what causes a supertaste?
more fungiform papillae
what are health consequences of taste variations?
diets can lead to disease, nontasters are more likely to drink and smoke
what is the specific hungers theory?
deficiency in a nutrient produces cravings for it
what is evidence for specific hungers theory?
boy craved salt because of a tumor, treatment for schizophrenia
what is evidence against specific hungers theory?
rats just avoided the diet that made them sick, children ate a variety of food because they were bored with just one
what is evidence that taste preferences are genetically determined?
children avoided odors unpleasant to their mothers
what is the labeled lines theory?
each nerve fiber carries a particular stimulus quality
what is evidence that preferences for chili peppers are learned?
chilis are added to the diet of children from a young age, children observe their family members
