Physiology of taste (pie)

Question 1

What type of receptors are the receptors for taste and smell ?

Answer 1

Chemoreceptors - they respond to particular chemicals

Question 2

What are the sensory receptors for taste mainly packaged in ?

Answer 2

Taste buds

Question 3

Describe the structure of teste buds

Answer 3

Taste buds consist of sensory receptor cells and support cells arranged like slices of orange

Question 4

Where are taste buds mainly present (hint this isn’t talking about specifically just the tongue)?

Answer 4

Tongue, palate, epiglottis, and pharynx

Question 5

How are signals from taste receptors transmitted to the brain?

Answer 5

Taste receptor cells, within taste buds, synapse with afferent nerve fibres these afferent nerve fibres then reach the brain via:

• VIIth cranial nerve (chorda tympani branch of facial nerve) - anterior two-thirds of the tongue
• IXth cranial (glossopharyngeal) nerve - posterior third of the tongue
• Xth caranial (vagus) nerve - areas other than tongue, including e.g. epiglottis and pharynx

Question 6

What specific location is the majority of taste buds found ?

Answer 6

The papillae in the tongue

Question 7

What are the 4 types of papillae, found in the tongue ?

Answer 7

1. Filliform: most numerous – do not contain taste buds
2. Fungiform
3. Vallate
4. Foliate

Question 8

What are the 5 primary types of taste ?

Answer 8

1. Salty
2. Sour
3. Sweet
4. Bitter
5. Umami (meaty or savory)

Question 9

Match the taste modality to the correct description:

1. Stimulated by chemical salts especially sodium chloride (NaCl)
2. Stimulated by acids which contain free hydrogen ions (H+)
3. Stimulated by configuration of glucose
4. Stimulated by diverse group of tastants, including e.g. alkaloids, poisonous substances and toxic plant derivatives
5. Triggered by amino acids especially glutamate

Sweet, Bitter, Umami, Salty, Sour

Answer 9

1. Salty: stimulated by chemical salts especially sodium chloride (NaCl)
2. Sour: stimulated by acids which contain free hydrogen ions (H+)
3. Sweet: stimulated by configuration of glucose
4. Bitter: stimulated by diverse group of tastants, including e.g. alkaloids, poisonous substances and toxic plant derivatives
5. Umami (meaty or savory): triggered by amino acids especially glutamate

Question 10

Define what augesia is and give an example of a cause

Answer 10

Loss of taste function e.g. due to nerve damage, endocrine disorders etc

Question 11

Define what hypoguesia is and give examples

Answer 11

Reduced taste function - e.g. by chemotherapy, medications etc

Question 12

Define what dysgeusia is and give examples

Answer 12

Distortion of taste function - e.g. glossitis; gum infections; tooth decay; reflux; upper respiratory infections etc