special senses- 3

Question 1

Chemical Senses

Answer 1

Taste and Smell

Question 2

The receptors for taste and smell are

Answer 2

chemoreceptors, which generate neural signals on binding with particular chemicals in their environment

Question 3

influence the flow of digestive juices and affect appetite.

Answer 3

The sensations of taste and smell in association with food intake

Question 4

Taste receptor cells are located

Answer 4

primarily within tongue taste buds

Question 5

Why do taste receptors have a life span of about 10 days

Answer 5

The taste receptor cells, by virtue of their task, frequently come into contact with potent chemicals.

Question 6

Sensory inputs are conveyed via

Answer 6

the brain stem and thalamus to the primary gustatory (or taste) cortex.

Question 7

We can discriminate among thousands of taste sensations, yet all tastes are varying combinations of five primary tastes:

Answer 7

Salty
Sour
Sweet
Bitter
Umami.

Question 8

The olfactory (“smell”) mucosa in the ceiling of the nasal cavity contains three cell types:

Answer 8

Olfactory receptor cells
Supporting cells
Basal cells

Question 9

What secretes mucus, which coats the nasal passages.

Answer 9

The supporting cells of the olfactory mucosa

Question 10

precursors for new olfactory receptor cells

Answer 10

The basal cells

Question 11

The sense of smell depends on

Answer 11

the olfactory receptor cells detecting odours, or scents.

Question 12

olfactory receptor cell

Answer 12

an afferent neuron whose receptor portion lies in the olfactory mucosa and traverses into the brain.

Question 13

form the olfactory nerve

Answer 13

The axons of the olfactory receptor cells collectively form the olfactory nerve.

Question 14

consists of several long cilia that extend to the surface of the mucosa.

Answer 14

The receptor portion of an olfactory receptor cell

Question 15

The receptor portion of an olfactory receptor cell consists of several long cilia that extend to the surface of the mucosa.
What do these cilia contain?

Answer 15

receptors for binding of odorants, molecules that can be smelled.

Question 16

During quiet breathing

Answer 16

odorants typically reach the sensitive receptors only by diffusion
The act of sniffing enhances this process.

Question 17

Odorants also reach the olfactory mucosa during eating by

Answer 17

wafting up to the nose from the mouth through the pharynx

Question 18

To be smelled, a substance must be:

Answer 18

1. Sufficiently volatile (easily vaporized) so
   that some of its molecules can enter the
   nose in the inspired air and
2. Sufficiently water soluble so that it can
   dissolve in the mucus coating the olfactory
   mucosa

Question 19

Various parts of an odour are detected by different olfactory receptors and sorted into

Answer 19

smell files

Question 20

Odour discrimination is coded by

Answer 20

patterns of activity in the olfactory bulb glomeruli.