Taste Flashcards
What is a main function of taste?
Avoidance of potentially toxic compounds
What section of the population are affected by chemosensory dysfunctions?
Elderly
What are chemoreceptors?
Receptors which are stimulated by chemical substances
What are 4 examples of chemoreceptors?
- Cutaneous nociceptors
- Circulatory sensors
- Olfactory receptors
- Taste receptors
Why do two nostrils receive slightly different chemical signatures?
Allows finer discrimination of odours
How are smells sensed?
Volatile chemicals are inhaled into nasal passages and stimulate olfactory receptors
What is the loss of smell called?
Anosmia
Name 5 taste sensations
- Salty
- Sour
- Bitter
- Sweet
- Umami
What is the loss of taste called?
Ageusia
What simulates a salty taste?
Positive charged sodium ions
What simulates a sour taste?
H⁺ ions
What stimulates a bitter taste?
Alkaloids
What stimulates a sweet taste?
Saccharine
What stimulates an umami taste?
Glutamate or MSG
Rank the 5 tastes from most sensitive to least sensitive
- Bitter
- Sour
- Umami
- Salty / Sweet
Name 4 places that taste buds can be found
- Tongue
- Palate
- Pharynx
- Epiglottis
What are 3 types of taste buds located on the dorsal surface of the tongue?
- Circumvallate
- Folate
- Fungiform papillae
Where are circumvallate taste buds found?
Medial margin at the rear of the tongue
Where are folate taste buds found?
Lateral margin at the rear of the tongue
Where are fungiform papillae taste buds found?
Anterior part of the tongue
What are taste cells?
Specialised epithelial cells organised into onion-shaped units called taste buds
What is the role of type I taste cells?
Supporting cells
What is the role of type II taste cells?
Contain receptors for sweet, bitter and umami tastes (possibly salty)
What is the role of type III taste cells?
Contain receptors for sour tastes
What is the role of type IV taste cells?
Basal cells which supply new taste cells
What is the lifetime of a taste-sensitive cell?
2 weeks
What nerves innervate taste buds?
Facial - Cranial VII
Glossopharyngeal - Cranial IX
Vagus - Cranial X
Give a brief account of how food is tasted
- Saliva carries food over taste buds
- Gustatory hairs causes gustatory cells to be stimulated
- Gustatory afferent nerve of cranial nerves carry signal to brain
- Chemicals detected translated to taste by brain
What provides flavour of food?
Central processing of taste and smell
Give 2 examples of dental products which can cause a taste disturbance
- Chlorhexidine - Bitter aftertaste
2. Sodium lauryl sulphate - Loss of sweet and salty taste
Give 2 examples of antibiotics which can cause a taste disturbance
- Doxycycline - Anosmia
2. Tetracycline - Metallic taste
What is the anatomical difference between supertasters, medium tasters and non-tasters?
The amount of fungiform papillae found in the anterior region of the tongue
