The Human Aerodigestive Tract and Gastroesophageal Reflux: An Evolutionary Perspective
Section snippets
Comparative Anatomy of the Mammalian Aerodigestive Tract: The Basic Pattern
Before exploring those specializations of the human aerodigestive tract that may be of particular interest to the clinician, it is important to outline the general “plan,” or condition, of this region in mammals. The class Mammalia is, of course, a large and varied group, including terrestrial and aquatic species who exhibit a range of dietary behaviors (e.g., herbivorous, omnivorous, carnivorous). Although no typical mammal can be said to exist, the general “plan” for their aerodigestive
Human Patterns: From the Basic Plan to a Unique Configuration
The aerodigestive tract of adult humans is the end product of both our evolutionary history as well as a unique ontogenetic process. Although all mammals undergo maturation of aerodigestive tract functions,[17]few species appear to undergo as radical a developmental rearrangement of structures in the region as do humans. Indeed, the dramatic changes that occur in the human aerodigestive tract, and the highly specialized end product, are hallmarks of Homo sapiens.
One of the most striking
The Human Aerodigestive Tract and GERD: A Template for Trouble
It is only by placing the adult human aerodigestive tract in the above developmental and comparative contexts that an appreciation can be gleaned of how our derived structural specializations affect both normal and abnormal upper respiratory and upper digestive behaviors. If we are to understand fully the human supraesophageal response to retrograde flow of gastroesophageal contents, we must first see how certain other mammals respond to retrograde incursions into their supraesophagus and, in
Acknowledgements
We wish to express our appreciation to Dr. Reza Shaker both for his invitation to Dr. Laitman to participate in the Symposium on Supra-esophageal Complications of Reflux Disease, and for creating the stimulating and productive environment at the symposium. Components of our research have been funded by Office of Naval Research (ONR) grant N00014-96-1-0764 and NSF Grants 9634519 and 9528100.
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Relationship Between Gastro-Oesophageal Reflux and Airway Diseases: The Airway Reflux Paradigm
2011, Archivos de BronconeumologiaGeneration of sound in marine mammals
2010, Handbook of Behavioral NeuroscienceCitation Excerpt :It is imperative to realize that the primary function of the larynx is not, as is commonly held, as a “voice box,” but rather as the protective guardian of the lungs (Reidenberg and Laitman, 2005). Indeed, the vocal folds (Fig. 1), a key element as the initial generator of sounds (fundamental frequencies) used in vocal communication, evolved as the primary protector against the incursion of foreign material into the trachea and lungs (Laitman and Reidenberg, 1997; Lipan et al., 2006). Additional roles evolved for these folds, including changing and maintaining intrathoracic and intra-abdominal pressures, activities essential for physiologic functions ranging from defecation, to lifting an object, to childbirth (Laitman and Reidenberg, 2009).
Ontogeny of postnatal hyoid and larynx descent in humans
2001, Archives of Oral BiologyCitation Excerpt :During swallowing, the coordination of supra- and infrahyoid muscles is partly a function of the spatial relations between the hyoid, epiglottis, mandible and mouth (Miller, 1982; Bosma, 1992; Palmer et al., 1992, 1997; Gay et al., 1994). However, hyo-laryngeal descent may be disadvantageous in humans because the low position of their hyoid causes the epiglottis to lose the ability to form a seal with the soft palate, increasing the risk of aspirating food, and of developing dysphagia from poor intermuscular coordination during deglutition (Dodds, 1989; Bosma, 1992; Palmer et al., 1992; Laitman and Reidenberg, 1997). Accurate ontogenetic data on the size and shape of the pharynx are needed to test hypotheses about the dual roles of hyo-laryngeal descent in deglutition and vocalization.
Gastroesophageal reflux disease and asthma in the adult
2001, Immunology and Allergy Clinics of North AmericaCitation Excerpt :The human adult is unique among mammals in having a larynx that is quite caudal in location. The infant larynx is positioned high in the neck, and there is progressive descent until the adult larynx lies between the lower border of C3 and the upper border of C7.63 Although the location and structure are beneficial to the quality of the voice, the low laryngeal position has negative features from the standpoint of respiration and swallowing crossing in close proximity.
Functional anatomy and physiology of the upper esophageal sphincter
2000, American Journal of MedicineCitation Excerpt :With a 5-mL swallow, the larynx moves superiorly approximately 2.5 cm and approximately 0.75 cm anteriorly.68 The hyoid and larynx elevation achieved during swallowing in adults recapitulates, if only momentarily, the high resting position of these structures in infancy and in nonhuman primates.78,79 Along with hyoid and laryngeal excursion, the high-pressure zone itself moves 2 to 2.5 cm in an orad direction.80–82
Neurobiology of Coughing in Children
2023, Journal of Clinical Medicine