Physiology of taste and smell Flashcards
What type of cells are the taste and smell receptors?
Chemoreceptors
What do they provide (protective effect)?
Quality control checkpoint as poisons taste bitter and off food smells bad and tastes sour/acidic
What is taste perception influenced by?
Information from the smell receptors
What is the medical name for taste?
Gustation
What is the organ of taste?
The taste bud
What is the half life of taste receptor cells?
10 days
What cells make up the taste bud?
receptor and support cells (and basal cells)
What is the function of basal cells?
-
Where are taste buds present?
Tongue, palate, epiglottis and pharynx
where do the majority of taste buds sit?
the paillae of the tongue
What are papillae?
Finger like projections that give rise to the rough appearance of the dorsum of the tongue
What are the 4 types of papillae?
Filliform, fungiform, vallate and foliate
Which papillae contain taste buds?
Fungiform, foliate and vallate
Which pallae are most numerous?
Filliform
How is taste conducted?
A tast provoking chemical will bind and produce a receptor potential (depolarising) and this iniates APs in afferent nerve fibres which will synapse with the receptor cells. The signals are conveys to the cortical gustatory areas via the brainstem and CN.
Which cranial nerves are involved in taste?
Facial nerve (via the chorda tympani) carries signal from the first 2/3 of the tongue.
Glossopharyngeal (9) will supply posterior third
Vagus (10) will supply areas other than the tongue.
What is the medical word for smell?
olfaction
What is Aguesia?
Loss of taste
What is hypogeusia?
Reduction in taste
What is dysgeusia?
Distortion of taste
What does each olfactory receptor cell have?
A thick and short dendrite and an expanded end called the olfactory rod
Where do cilia project from into the olfactory mucosa?
the olfactory rods
How many cillia per rod?
10-12
What is the life span of an olfactry receptor?
2 months
