15: Olfactory and taste organ

Question 1

Define macrosmatic

Answer 1

Highly developed sense of smell/reliance on olfactory system

Question 2

Define microsmatic

Answer 2

Weakly developed sense of smell/ less reliance on olfactory system

Question 3

How long is a dog’s epithelium compared to humans?

Answer 3

dog: 10sq inches, humans: 1 sq inch

Question 4

How many olfactory receptor genes do humans have?

Answer 4

300-400 different types

Question 5

Tell me about the primary sensory receptor cells + cilia (how many)

Answer 5

50 million primary sensory receptor cells w 8-20 cilia down in a layer of mucus of about 60 microns thick

Question 6

The location of olfactory receptors + why

Answer 6

In the roof of nasal cavity + prevention from flooding

Question 7

Why is the olfactory receptor close to the brain?

Answer 7

Fast sensing for toxic gases

Question 8

After how many days are olfactory receptors regenerated?

Answer 8

30-60 days

Question 9

What do the Bowman’s glands produce?

Answer 9

mucus

Question 10

T/F: The number of receptors do not determine olf sensitivity

Answer 10

False

Question 11

What is our binding capacity?

Answer 11

300-400 diff types of OR gene, about 50 million receptor cells

Question 12

T/F: Olfactory pathway is the direct connection to the brain

Answer 12

true

Question 13

8 steps of physiology of olfaction

Answer 13

1. Molecules dissolved in mucus
2. Combination w/ receptors on cilia
3. G-protein stimulation
4. Adenyl Cyclase activated
5. Increase IC cAMP
6. Opening of Na+ channels
7. Na+ influx
8. Depolarization

Question 14

What is Anosmia?

Answer 14

Absence of the sense of smell

Question 15

What is Dysosmia?

Answer 15

Disturbed sense of smell

Question 16

What is Hyposomia?

Answer 16

Reduced sense of smell (Vit. A deficiency and hypogonadism)

Question 17

What is Hyperosmia?

Answer 17

Increased sense of smell (Adrenal insufficiency)

Question 18

What is Ageusia?

Answer 18

Absence of sense of taste

Question 19

What is Dysgeusia?

Answer 19

Disturbed sense of taste?

Question 20

What is Hypogeusia?

Answer 20

Diminished sense of taste

Question 21

What is Hypergeusia?

Answer 21

Increased sense of taste

Question 22

Are taste and smell closely linked ?

Answer 22

Yes, but involve different receptors and receptive processes –> suggests an overlap in central processing

Question 23

How long after do taste bud cells regenerate?

Answer 23

10 days

Question 24

Location and structure of taste sensors

Answer 24

Location: top of tongue for access to food molecules
Designed to increase sensitivity
(SA)

Question 25

How many taste buds are found on tongue
+ soft palate + pharynx?

Answer 25

~10 000 taste buds

Question 26

How many receptor cells do taste buds consist of?

Answer 26

~50 receptor cells (type 3) surrounded by supporting cells
Basal cells (type 1&2) develop into supporting cells or Gustatory receptor cells

Question 27

Physiology of taste

Answer 27

dissolution in saliva –> attachment to receptors –> generator potential –> action potential

Question 28

What is the taste perception influenced by?

Answer 28

Odor, temperature and texture, psychological experiences w past experiences w food influence taste

Question 29

The receptors of sweetness

Answer 29

T1R genes (3 types, sweetness) - T2R genes (28 types, bitterness)