TASTE/SMELL PT 2

Question 1

describe olfacton threshold

Answer 1

low threshold, only a few molecules need to be present

Question 2

does adaption happen quick

Answer 2

yes

Question 3

describe olfactory receptors adaption

Answer 3

adapt by 50% in the first second or so and more slowly thereafter

Question 4

describe complete adaption to certain strong odors

Answer 4

occurs in about 1 minute after exposure

Question 5

what are the olfactory areas in the brain

Answer 5

hippocampus, amyglada, orbital frontal cortex, thalamus

Question 6

wha are taste buds

Answer 6

Sensory receptors for taste

Question 7

where are taste buds located

Answer 7

Located on tongue, cheeks, soft palate, pharynx, epiglottis
Most on tongue (~10,000)

Question 8

what are papillae and what do they give the tongue

Answer 8

visible, peglike structures
Give tongue an abrasive feel

Question 9

what does each taste bud consist of

Answer 9

50 – 100 epithelial cells of two major types

Question 10

what are the two major types of epithelial cells that taste buds consist of

Answer 10

Gustatory epithelial cells; Basal epithelial cells

Question 11

describe size of taste buds

Answer 11

microscopic

Question 12

describe basal epithelial cells

Answer 12

Act as stem cells → dividing and differentiating into new gustatory epithelial cells

Question 13

what are gustatory epithelial cells

Answer 13

taste cells; spindle-shaped chemoreceptors

Question 14

where does the peripheral end of the gustatory epithelial cell terminate

Answer 14

terminates at gustatory (taste) pore with fine hair filaments, i.e. gustatory hairs

Question 15

what do microvilli do at termination site

Answer 15

Microvilli project through taste pore into saliva

Question 16

what are microvilli subject to

Answer 16

Subject to friction and frequently burned → Replaced every 7–10days

Question 17

what do dendrites in each taste bud do

Answer 17

take signal from receptor cell to the brain

Question 18

what are the five major classes of taste

Answer 18

sweet, sour, salty, bitter, umami

Question 19

describe sour

Answer 19

acids (H+)

Question 20

describe sweet

Answer 20

elicited by organics (sugars/salts)

Question 21

describe salty

Answer 21

inorganic salts (metal ions/NaCl)

Question 22

describe bitter

Answer 22

alkaloids (caffeine/nicotine)

Question 23

describe umami

Answer 23

amino acids (glutamate/aspartate)

Question 24

what are other tastes, like chocolate and coffee, created by

Answer 24

combinations of these five & accompanying olfactory sensations

Question 25

how do cravings and taste preferences happen

Answer 25

Likes and dislikes have homeostatic value » Craving: may be indication of body’s need

Question 26

how can taste sensations be protective

Answer 26

Can be protective !! Intense dislike for extreme sour/bitterness warns of spoilage !! Many natural poisons and spoiled foods are bitter

Question 27

what must happen for a chemical to be tasted

Answer 27

Must dissolve in saliva, diffuse into taste pore and contact the gustatory hairs

Question 28

what induces depolarization

Answer 28

Binding of a chemical to gustatory cell

Question 29

how are different guastory cells different

Answer 29

Different gustatory cells have different thresholds for activation (bitter receptors detect minute amounts)

Question 30

what happens after neurotransmitter binds to associated afferent fiber (dendrite)

Answer 30

Triggers dendrite graded potential → Moves information to the 1st order neurons

Question 31

how long does it take receptors to partially and fully adapt

Answer 31

Receptors partially adapt in 3-5s, completely adapt in 1-5min

Question 32

describe chemical depolarization of salty taste

Answer 32

Na+ influx through Na+ channels

Question 33

describe chemical depolarization of sour taste

Answer 33

H+ blockade of K+ channels → Allows cations to enter

Question 34

describe chemical depolarization of bitter/sweet/umami

Answer 34

Receptor coupled w/ GPCR which leads to opening cation

Question 35

whats the vagus nerve (X)

Answer 35

just need to know vagues nerve correlates with PNS because stimulated witth taste pretty much every sensosyr neuron w thalamus

Question 36

where is the sweet taste on tongue

Answer 36

tip

Question 37

where is salty and sour taste on tongue

Answer 37

sides

Question 38

where is the bitter taste on tongue

Answer 38

back

Question 39

where is the umami taste on tongue

Answer 39

pharynx

Question 40

but do tastes stilll come from all areas

Answer 40

yes

Question 41

what receptors does the mouth have

Answer 41

thermo-, mechano-, and nociceptors

Question 42

what can enhance or detract from food taste

Answer 42

Temperature, texture, pain (spice

Question 43

how much of taste is smell

Answer 43

80%

Question 44

whats Dysosmia

Answer 44

distorted sense of smell

Question 45

whats Anosmias

Answer 45

absence of smell

Question 46

whats hyposmia

Answer 46

impaired sense of smell

Question 47

what causes damage to olfactory epithelium and is it permanent

Answer 47

Inhalation of toxic fumes Physical injury to interior of nose Some nasal sprays usually temporary but can be permanent

Question 48

whats Dysgeusia

Answer 48

distorted sense of taste

Question 49

whats ageusia

Answer 49

absence of taste

Question 50

whats hypogeusia

Answer 50

decreased sensitivty

Question 51

whats hypergeusia

Answer 51

increased senstibty

Question 52

what are the four kinds of papilale

Answer 52

fungiform, foliate, circumvallate, filiform