Physiology - Taste and Smell

Question 1

Which type of receptors are taste and smell receptors?

Answer 1

Chemoreceptors

Question 2

How is taste perception influenced?

Answer 2

Smell receptors

Question 3

What are the sense organs of taste?

Answer 3

Taste buds

Question 4

What is the life span of a taste bud?

Answer 4

10 days

Question 5

Taste receptor cells are replaced with what?

Answer 5

Basal cells

Question 6

Where are taste buds mainly present?

Answer 6

1. Tongue
2. Palate
3. Epiglottis
4. Pharynx

Question 7

What are the most abundant type of papillae on the tongue?

Answer 7

Filiform

Question 8

How is a depolarising receptor potential initiated within taste buds?

Answer 8

Taste provoking chemicals bind to receptor cells allowing ionic channels to open

Question 9

How do afferent taste fibres reach the brainstem?

Answer 9

Chorda tympani (anterior 2/3rds)

Glossopharyngeal nerve (posterior 1/3rd)

Vagus nerve (other areas associated with taste)

Question 10

How many primary tastes are there?

Answer 10

5

Question 11

Which cell types are present in the olfactory mucosa?

Answer 11

1. Olfactory receptor cells
2. Supporting cells
3. Basal cells (secrete mucous)

Question 12

What comprises olfactory receptors?

Answer 12

Specialised endings of renewable afferent neurones

Question 13

Each neurone associated with the olfactory receptors has what at one end?

Answer 13

Olfactory rod (expanded area)

Question 14

What projects from the surface of the olfactory mucosa?

Answer 14

Cilia

(to which odourants bind)

Question 15

What act as precursors for new olfactory cells?

Answer 15

Basal cells

Question 16

How does sensory information from the cilia assoaited with olfactory receptors reach the brain?

Answer 16

1. Axons of olfactory nerves for afferent nerves
2. Pierce cribriform plate and enter olfactory bulbs
3. Olfactory bulbs pass signal along olfactory tracts
4. Signal reaches temporal lobe and olfactory tract

Question 17

Why does the act of sniffing enhance smelling?

Answer 17

Odourants only reach the smell receptors by diffusion otherwise

Question 18

Which two characteristics does a substance require to be smelt?

Answer 18

1. Sufficiently volatile
2. Sufficiently water soluble (dissolves in mucus coating olfactory mucosa)

Question 19

What is the term given to the inability to smell?

Answer 19

Anosmia

Question 20

What are the causes of anosmia?

Answer 20

1. Viral infections
2. Allergy
3. Nasal polyps
4. Head injury

Question 21

What is the term given to a reduced ability to smell?

Answer 21

Hyposmia

Question 22

Hyposmia may be an early sign for which condition?

Answer 22

Parkinson’s disease

Question 23

What is the term given to an altered sense of smell?

Answer 23

Dysosmia