Epiglottal taste buds and different feeding habits of mammals

Abstract

Introduction: Taste buds which occur on the laryngeal surface of epiglottis of mammals share many similarities with lingual taste buds, although their function is different. These taste buds mediate reflex action to close the laryngeal opening or initiate the cough reflex when food comes in contact with the posterior surface of the epiglottis.

Methods: Repeated microscopic studies were carried out on 6 μm serial haematoxylin and eosin stained sections of epiglottides of buffalo, guinea pig, house rat, human, lamb and rabbit. Quantitative investigation was carried out on the taste buds on the rostral, middle and caudal regions of the epiglottides of each of these mammals. Relative frequency of occurrence value for comparative assessment of taste buds is proposed here.

Results: The average number of taste buds was found higher in the herbivorous buffalo, goat and rabbit; while the number was lower in the omnivorous guinea pig, house rat and the human. The density of taste buds was found to be directly proportional to the feeding behaviour of mammals, showing their significant role in inducing reflexes for safe passage of bolus through the oesophagus and for prevention of the respiratory tract congestion.

Conclusion: Since the number of taste buds was found higher in the herbivorous mammals, it was concluded that the bigger the volume of the bolus the higher is the density of epiglottal taste buds. These taste buds are adapted to protect the respiratory passage during swallowing and drinking by initiating the reflex action.