Taste

Question 1

insular cortex

Answer 1

The primary cortical processing area for taste—the part of the cortex that first receives taste information. Also called insula or gustatory cortex.

Question 1

sour

Answer 1

One of the four basic tastes; the taste quality produced by the hydrogen ion in acids.

Question 1

taste bud

Answer 1

A globular cluster of cells that has the function of creating neural signals conveyed to the brain by the taste nerves. Some of the cells in a taste bud have specialized sites on their apical projections that interact with taste stimuli. Some of the cells form synapses with taste nerve fibers.

Question 1

taste receptor cell

Answer 1

A cell within the taste bud that contains sites on its apical projection that can interact with taste stimuli. These sites fall into two major categories: those interacting with charged particles (e.g., sodium and hydrogen ions), and those interacting with specific chemical structures.

Question 2

retronasal olfactory sensation

Answer 2

The sensation of an odor that is perceived when chewing and swallowing force an odorant in the mouth up behind the palate into the nose. Such odor sensations are perceived as originating from the mouth, even though the actual contact of odorant and receptor occurs at the olfactory mucosa.

Question 3

microvilli

Answer 3

Slender projections of the cell membrane on the tips of some taste bud cells that extend into the taste pore.

Question 4

specific hungers theory

Answer 4

The idea that deficiency of a given nutrient produces craving (a specific hunger) for that nutrient. Curt Richter first proposed this theory and demonstrated that cravings for salty or for sweet are associated with deficiencies in those substances. However, the idea proved wrong for other nutrients (e.g., vitamins).

Question 5

chorda tympani

Answer 5

The branch of cranial nerve VII (the facial nerve) that carries taste information from the anterior, mobile tongue (the part that can be stuck out). The chorda tympani exits the tongue with the lingual branch of the trigeminal nerve (cranial nerve V) and then passes through the middle ear on its way to the brain.

Question 5

orbitofrontal cortex (OFC)

Answer 5

The part of the frontal lobe of the cortex that lies behind the bone (orbit) containing the eyes. The OFC is responsible for the conscious experience of olfaction, as well as the integration of pleasure and displeasure from food; and it has been referred to as the secondary olfactory cortex and secondary taste cortex. The OFC is also involved in many other functions, and it is critical for assigning affective value to stimuli—in other words, determining hedonic meaning.

Question 7

dimer

Answer 7

A chain of two molecules.

Question 9

supertaster

Answer 9

An individual whose perception of taste sensations is the most intense. A variety of factors may contribute to this heightened perception; among the most important is the density of fungiform papillae.

Question 11

bitter

Answer 11

One of the four basic tastes; the taste quality, generally considered unpleasant, produced by substances like quinine or caffeine.

Question 12

nontaster (of PTC/PROP)

Answer 12

An individual born with two recessive alleles for the TAS2R38 gene and unable to taste the compounds phenylthiocarbamide and propylthiouracil.

Question 13

tastant

Answer 13

Any stimulus that can be tasted.

Question 14

cross-modality matching

Answer 14

The ability to match the intensities of sensations that come from different sensory modalities. This ability enables insight into sensory differences. For example, a listener might adjust the brightness of a light until it matches the loudness of a tone.

Question 15

taster (of PTC/PROP)

Answer 15

An individual born with one or both dominant alleles for the TAS2R38 gene and able to taste the compounds phenylthiocarbamide and propylthiouracil. PTC/PROP tasters who also have a high density of fungiform papillae are PROP supertasters.

Question 16

labeled lines

Answer 16

A theory of taste coding in which each taste nerve fiber carries a particular taste quality. For example, the quality evoked from a sucrose-best fiber is sweet, that from an NaCl-best fiber is salty, and so on.

Question 17

fungiform papillae

Answer 17

Mushroom-shaped structures (maximum diameter 1 millimeter) that are distributed most densely on the edges of the tongue, especially the tip. Taste buds (an average of six per papilla) are buried in the surface.

Question 18

basic taste

Answer 18

Any of the four taste qualities that are generally agreed to describe human taste experience: sweet, salty, sour, bitter.

Question 20

monosodium glutamate (MSG)

Answer 20

The sodium salt of glutamic acid (an amino acid).

Question 21

filiform papillae

Answer 21

Small structures on the tongue that provide most of the bumpy appearance. Filiform papillae have no taste function.

Question 21

heterodimer

Answer 21

A chain of two molecules that are different from each other.

Question 22

flavor

Answer 22

The combination of true taste (sweet, salty, sour, bitter) and retronasal olfaction.

Question 23

sweet

Answer 23

One of the four basic tastes; the taste quality produced by some sugars, such as glucose, fructose, and sucrose. These three sugars are particularly biologically useful to us, and our sweet receptors are tuned to them. Some other compounds (e.g., saccharin, aspartame) are also sweet.

Question 24

umami

Answer 24

The taste sensation produced by monosodium glutamate.

Question 26

salty

Answer 26

One of the four basic tastes; the taste quality produced by the cations of salts (e.g., the sodium in sodium chloride produces the salty taste). Some cations also produce other taste qualities (e.g., potassium tastes bitter as well as salty). The purest salty taste is produced by sodium chloride (NaCl), common table salt.

Question 27

cranial nerves

Answer 27

Twelve pairs of nerves (one for each side of the body) that originate in the brain stem and reach sense organs and muscles through openings in the skull.

Question 28

foliate papillae

Answer 28

Folds of tissue containing taste buds. Foliate papillae are located on the rear of the tongue lateral to the circumvallate papillae, where the tongue attaches to the mouth.

Question 29

circumvallate papillae

Answer 29

Circular structures that form an inverted V on the rear of the tongue (three to five on each side, with the largest in the center). Circumvallate papillae are moundlike structures surrounded by a trench (like a moat). These papillae are much larger than fungiform papillae.

Question 30

papilla

Answer 30

Any of multiple structures that give the tongue its bumpy appearance. From smallest to largest, the papilla types that contain taste buds are fungiform, foliate, and circumvallate; filiform papillae, which do not contain taste buds, are the smallest and most numerous.