Taste and olfaction Flashcards
Inability to taste
Aguesia
Decreased ability to taste
Hypogeusia
Distorted ability to taste
Dysguesia
Sensation of bad taste in the absence of appropriate gustatory stimuli
Cacoguesia
Any substance capable of stimulating the sense of taste
Tastant
Inability to detect odours
Anosmia
Decreased ability to detect odours
Hyposmia
Distorted identification of smell
Dysosmia
Altered perception in the presence of an odour
Parosmia
Perception of smell without an odour present
Phantosmia
Inability to classify or contrast odours, although able to detect odours
Agnosia
Shape of taste buds
Onion shaped
Composed of 50-80 spindle shaped cells
How are taste buds separated by the underlying connective tissue
Basement membrane
How do taste buds communicate with oral environment
Taste pore
Three types of taste buds classification
Type I, II and III
Taste buds are a labile population, what does this mean
Continually being renewed, they are continuously turning over
Specialised type of epithelium on the dorsum of the tongue
Gustatory epithelium
5 categories of taste that taste buds recognise
Sweet Salty Bitter Sour Umami
Which type of papillae on the tongue does not have taste buds
Filiform
Type I (Glial- like cells)
- Most common (50% of taste bud cells)
- Degrade/ absorb neurotransmitters
- Important in the transduction of salty taste
Type II (Receptor cells)
- Sweet, bitter, umami tastes activate receptor cells
Contain vesicles
Adjacent to intra- epithelial nerves
Continually replaced
Apical ends of the type II cells joined together by junctional complexes
Microvilli project into the pores from their apical end
Type III (Pre- synaptic cells)
- Receive input and are functionally connected to receptor cells
Form synaptic junctions with nerve terminals
Important in sour taste
Cells in the olfactory epithelium
Olfactory receptor cells
Supporting cells
Basal cells
Brush cells
Labile population
What happens in the olfactory bulb
Neurones synapse with olfactory ‘mitral’ cells which then pass info to various parts of the brain
It is the only sensory pathway which does not relay in the thalamus
Axons pass to various cortical regions
