Secondary sentient sense organs contain neuroepithelial receptor cells that interact with stimuli and generate nerve impulses that are transmitted to sensory neurons. The organ of taste contains taste buds located on lingual papillae in the tongue. Taste buds are epithelial structures containing supporting cells, neuroepithelial cells that are chemoreceptors, and basal cells. Neuroepithelial cells in taste buds synapse with afferent and efferent nerve fibers including the chorda tympani nerve, glossopharyngeal nerve, and superior laryngeal nerve.

1. Secondary Sentient Sense Organs
Lecturer – professor Boronikhina Tatiana Vladimirovna

2. Secondary sentient sense organs contain neuroepithelial
receptor cells
 Neuroepithelial cells form synapses with sensory neuron dendrites
 Neuroepithelial cells interact with stimuli
⇓
generate nerve impulses
⇓
transmit impulses to sensory neurons
dendrite
°°°°

3. Hearing Equilibrium Taste

4. Organ of taste
 receptor field consists of the taste bauds
 taste buds are located on the lateral surface
of lingual papilae
⇐
tongue ⇒
dorsal surface

5. Lingual papillae are projections of the mucosa
on the tongue dorsal surface
Papilla structure:
 stratified squamous partially keratinized epithelium
 a central core (primary papilla) – LCT
 taste buds occupy the epithelium of the lateral papilla surface
⇓
⇑
taste bud is an ovoid
intraepithelial structure

6. Lingual papilla types
 filiform papillae are covered by keratinized epithelium
and lack the taste buds ⇒

7. Taste buds are epithelial structures
 epithelial cells are arranged around the taste pit
 taste pore leads to the taste pit
taste pore
⇓

8. Taste bud morphology
taste pore
⇓
photomicrograph
⇓
electron micrograph
⇒

9. Taste bud cells
 supporting cells
 neuroepithelial cells
 basal cells (stem cells)

10. Taste bud neuroepithelial cells are chemoreceptors
 Apical cell surface possesses microvilli
 pass through the taste pore
 are bathed by saliva
 contain membrane chemoreceptors for taste molecules
microenvironment - saliva
⇓

11. Taste bud innervation
 Neuroepithelial cell basal portion synapses with
afferent and efferent nerve fibres
⇒
• chorda tympani of n. facialis (VII)
⇐
• n. glossopharyngeus (IX)
⇐
• from taste buds of the epiglotis
n. loryngeus superior of n. vagus (X)

12. Sensory neurons of the taste analyzer
 are in sensory ganglia associated
with the cranial nerves:
• n. facialis
• n. glossopharyngeus
• n. vagus

13. Taste bud neuroepithelial cell differentiation
 Perception of the taste sensations
bitter ⇒
sour (acid) ⇒
salt ⇒
sweet ⇒

14. Thank you for attention!