this is the incmplete slide

1. INTRODUCTION TASTE QUALITIES PHYSIOLOGY
PRESENTATION
PHYSIOLOGY OF TASTE
Anatomy of taste bud Species difference in taste perception
Physiology of taste 1

2. INTRODUCTION
• Tongue is the muscular Organ filling the oral cavity
• The many papillae on its dorsal surface are named
according to their shape and grouped on the basis of
their function :
Mechanical papillae
• filiform papillae
• conical papillae
• marginal papillae
Gustatory papillae
• fungiform papillae
• vallate papillae
• foliate papillae
Physiology of taste 2

3. INTRODUCTION
The sense of taste (gustation ) is essential in order for an animal,
• To monitor what it eats and drinks ,
• To determine if the contents of the mouth should be swallowed or rejected
• Taste cells are organized in clusters called Taste buds .
• Taste cells are axon – free sensory cells
• Number of taste buds varies according to species :
Ungulates ( Post . Region) 10,000 – 20,000
Cats 500
Dogs ( Tip) 2000
Chicken (Gullet ) 20 -30
Humans 5000
Physiology of taste 3

4. TASTE BUD
 Taste Buds are barrel shaped in structure measuring 50 – 70 µm
 Location of taste buds : Sidewalls of tongue papillae on upper surface of tongue, soft
palate , pharynx , epiglottis.
COMPONENT
S
Cells
Taste chamber
Taste pores
Physiology of taste 4

5. TASTE BUD
Taste chamber
• Gel like material
• Contains Glycosaminoglycans , Vit C & Enzyme
Taste pores
• It is simply an opening with diameter 2-10 µm
• Several microvilli protrude out into taste pore from taste cell
Physiology of taste 5

6. TASTE BUD
Cells
Sustentacular / Supporting cells (dark )
Gustatory /receptor cells (light cells )
Basal cells
Physiology of taste 6

7. TASTE BUD
Cells
Physiology of taste 7

8. TASTE BUD
Gustatory /receptor cells
• Each taste bud contains 100 receptor
cells.
• Cells are bipolar in shape ,extending
from opening to base
• Short life span (10 days )
• Micro – villi protrude into oral cavity &
contact with saliva
Physiology of taste 8

9. TASTE BUD
Basal cells
• Small round cell at the
bottom of taste buds
• They are stem cells
continuously differentiated
into taste cells
Physiology of taste 9

10. TASTE BUD
Sustentacular cells
• Supporting cells
• Each taste buds is innervated by 50 nerve fibres &
each nerve fibre in turn receives inputs from all
taste buds
• Tactile & temperature receptors are innervated by
trigeminal nerve
Physiology of taste 10

11. Physiology of taste 11
 Stimulus: Food or liquid enters the mouth
 Dissolution: Taste molecules dissolve in saliva
 Taste Bud Encounter: Taste molecules come into contact with
taste bud pore
 Taste Receptor Interaction:
 Specific Binding: Taste molecules bind to specific receptors on
taste bud cells (e.g., T1R2+T1R3 for sweet, proton receptors for
sour)
 Ligand Recognition: If a match occurs (correct molecule for
receptor), a signal is initiated.
Mechanism of Taste

12. Physiology of taste 12
Mechanism of Taste
 Signal Transduction Pathway (Depends on Receptor Type):
• G Protein-Coupled Receptor (GPCR)
• Ligand binding directly leads to changes in ion channel
permeability.
 Electrical Signal Generation:
• Influx of cations (like Na+) or efflux of anions (like Cl-) creates
an electrical signal within the taste bud cell due to altered ion
channel permeability.
 Neurotransmitter Release: Electrical signal triggers the release
of neurotransmitters (e.g., glutamate) from the taste bud cell.