• Lot of people asked me many times , why some people have better sense of taste or how the taste sense functions in human biology. Just trying to pen down the mystery behind the science. People love to eat but don’t want to go behind the taste… Lets take a look
• Taste & smell:

Both determine the flavour of food

Taste and smell are closely linked even though they involve different receptors

and receptive processes.

This suggests an overlap in central processing

Taste and smell:

• Receptors are chemoreceptors
• In association with food intake, influence flow of digestive juices and affect appetite
• Stimulation of receptors induces pleasurable or objectionable sensations and signals presence of something to seek or to avoid
• Chemoreceptors housed in taste buds
• Present in oral cavity and throat
• Taste receptors have life span of about 10 days
• Taste bud consists of
  • Taste pore
    • Opening through which fluids in mouth come into contact with surface of receptor cells
  • Taste receptor cells
    • Modified epithelial cells with surface folds called microvilli
    • Plasma membrane of microvilli contain receptor sites that bind selectively with chemical molecules
  • Located in taste buds in:
    • Tongue
    • Epiglottis
    • Soft Palate
    • Pharynx
    • Anatomy of the Taste Buds
    • 10,000 taste buds found on tongue, soft palate & pharynx
    • Taste buds consist of:
    • ~50 receptor cells (type 3) surrounded by supporting cells
    • Basal cells (type 1 &2) develop into supporting cells then receptor cells
    • Gustatory hairs project through the taste pore
    • Life span of 10 days
  • Tastant (taste-provoking chemical)
  • Binding of tastant with receptor cell alters cell’s ionic channels to produce depolarizing receptor potential
  • Receptor potential initiates action potentials within terminal endings of afferent nerve fibers with which receptor cell synapses
  • Terminal afferent endings of several cranial nerves synapse with taste buds in various regions of mouth
  • Signals conveyed via synaptic stops in brain stem and thalamus to cortical gustatory area

Physiology of Taste –

• Dissolution in Saliva
• Attachment to Receptors
• Generator Potential
• Action Potential
• Taste Perception
• Influenced by information derived from other receptors, especially odor
• Temperature and texture of food influence taste
• Psychological experiences associated with past experiences with food influence taste
• How cortex accomplishes perceptual processing of taste sensation is currently unknown

Primary modalities of taste

• Responses of Taste buds:
• Each taste bud responds strongly to one type of taste
• But they also respond to other tastes as well
•  
• 5 primary tastes
• Salty
• Stimulated by chemical salts, especially NaCl
• Sour
• Caused by acids which contain a free hydrogen ion, H⁺
• Sweet
• Evoked by configuration of glucose
• Bitter
• Brought about by more chemically diverse group of taste substances
• Examples – alkaloids, toxic plant derivatives, poisonous substances
• Umami
• Meaty or savory taste/ pleasant taste
• Clinical considerations
• Ageusia: Absence of sense of taste
• Dysgeusia: Disturbed sense of taste
• Hypogeusia: Diminshed sense of taste
• Hypergeusia: increased sense of taste

I am sure this blog will bring some clarity as to how our taste buds function in our system.. However feel free to ask questions…