Chapter 4: Sensation and Perception 4.6 (Smell and Taste)

Question 1

Odourant molecules

Answer 1

chemicals drifting in on the air we breathe that make their way into our noses (nasal cavity) to the olfactory epithelium where they bind to olfactory receptor neurons (ORNs)

Question 2

Olfactory epithelium

Answer 2

mucous membrane situated along the top of the nasal cavity which contains around 10m olfactory receptor neurons

Question 3

Olfactory receptor neurons (ORNs)

Answer 3

receptor cells that transduce odourant molecules into neural impulses; each has a receptor that binds only to certain odourants

Question 4

Olfactory bulb (1 in each hemisphere)

Answer 4

brain structure located above the nasal cavity beneath the frontal lobes, where the axons of groups of ORNs sensitive to the same odourant are sent from the olfactory epithelium directly to the brain (frontal lobe)

Question 5

Olfactory sensitivity and acuity

Answer 5

ability to detect odors and ability to discriminate among odors

Question 6

What parts of the brain does the olfactory bulb send information to?

Answer 6

frontal lobe, amygdala, hippocampus, and other forebrain structures almost directly

Question 7

Pheromones

Answer 7

biochemical odourants emitted by other members of an animal’s species that can affect its (social and reproductive) behavior or physiology of animals

Question 8

5 main types of taste receptors

Answer 8

salt, sour, bitter, sweet, and umami (savory, food with a high concentration of protein)

Question 9

Papillae

Answer 9

thousands of small bumps covering the tongue that are easily visible to the naked eye

Question 10

Taste buds

Answer 10

organs of taste transduction contained in the papilla that are evenly distributed over the tongue, roof of the mouth, and upper throat, each containing taste receptor cells

Question 11

Microvilli

Answer 11

tips of the taste receptor cells in taste buds that react with tastant molecules in food

Question 12

Taste vs. flavor

Answer 12

Taste is the contribution made by receptors in your mouth alone. Taste and smell collaborate to produce complex perception of flavor (mutisensory).

Question 13

What are areas of the brain sensitive to odor?

Answer 13

Primary olfactory cortex (near amygdala), primary gustatory cortex (in the frontal lobe), mouth region of primary somatosensory cortex (in parietal lobe)

Question 14

How does taste travel to the brain?

Answer 14

tastant molecules dissolve in saliva and stimulate microvilli, then taste information is carried from the taste buds, through the cranial nerve, to the brainstem, thalamus, then the primary gustatory cortex in the frontal lobe

Question 15

How do we experience smell?

Answer 15

When you smell something, odorants pass into your nose and nasal cavity. Olfactory receptor neurons in the olfactory epithelium transmit the signal to the olfactory bulb, then along the olfactory nerve to areas of the cortex and amygdala.

Question 16

Which areas of the brain does smell have a close relationship with?

Answer 16

areas involved in emotional and social behavior, and memory

Question 17

Top-down processing in perceiving smell

Answer 17

Perception of smell can be influenced by our previous experiences i.e. the same sensation can be perceived differently

Question 18

Supertaster

Answer 18

Has relatively more taste buds, better ability to detect taste, above 35 papillae (blue flood coloring and wax paper test)

Question 19

Hypotaster

Answer 19

has relatively fewer taste buds, worse ability to detect taste

Question 20

Is taste perception genetic or learned?

Answer 20

Some are genetic while others are learned

Question 21

How are the primary olfactory (smell) and gustatory (taste) cortex interconnected?

Answer 21

Gustatory cortex passes taste information directly to the olfactory cortex