Skip to main content
SpringerLink
Log in

Airway protective mechanisms: Current concepts

  • Published:
Dysphagia Aims and scope Submit manuscript

Summary

There are at least eight mechanisms identified that result either in volume clearance of the pharynx and esophagus (secondary peristalsis and pharyngeal swallow) or prevent entry of the gastric content into the esophagus and pharynx (LES and UES), accentuate these barriers (esophago-UES and pharyngo-UES contractile reflexes), or induce closure of the vocal cords and introitus to the trachea (esophagoglottal and pharyngoglottal reflexes). The sum effect of various combinations of these mechanisms is suggested to help prevent retrograde aspiration. In other words, airway protective mechanisms against retrograde aspiration are multifactorial and involve delicate interaction between upper GI and upper airway tracts. Although the existence of these mechanisms in normal volunteers has been documented, their function in patients with retrograde aspiration and supraesophageal complications of gastroesophageal reflux disease currently awaits investigation.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Shaker R, Dodds WJ, Helm JF, Kern MK, Hogan WJ: Regional esophageal distribution and clearance of refluxed gastric acid. Gastroenterology 101:355–359, 1991

    Google Scholar 

  2. Osler WB: The Principles of Medicine. New York, NY: Appleton, 1892

    Google Scholar 

  3. Kjellen G, Tibbling I, Wranne B: Effect of conservative treatment of esophageal dysfunction on bronchial asthma. Eur J Respir Dis 62:190–197, 1981

    Google Scholar 

  4. Perrin-Fayolle M, Gormand F, Brazillon G: Long-term results of surgical treatment for gastroesophageal reflux in asthmatic patients. Chest 96:40–45, 1989

    Google Scholar 

  5. Goodall RJR, Earis JE, Cooper DN: Relationship between asthma and gastroesophageal reflux. Thorax 36:116–121, 1981

    Google Scholar 

  6. Koufman JA: The otolaryngologic manifestations of gastroesophageal reflux disease (GERD): a clinical investigation of 225 patients using ambulatory 24-hour pH monitoring and an experimental investigation of the role of acid and pepsin in the development of laryngeal injury. Laryngoscope 101:1–78, 1991

    Google Scholar 

  7. Shaker R, Milbrath M, Ren J, Toohill RJ, Hogan WJ, Li Q, Hoffmann C: Esophagopharyngeal distribution of refluxed gastric acid in patients with refexology. Gastroenterology, in press

  8. Koufman JA, Wiener GJ, Wu WC, Castell DO: Reflux laryngitis and its sequelae: the diagnosic role of ambulatory 24-hour pH monitoring. J Voice 2(1):78–89, 1988

    Google Scholar 

  9. Wiener GJ, Koufman JA, Wu WC, Cooper JB, Richter JE, Castell DO: Chronic hoarseness secondary to gastroesophageal reflux disease: documentation with 24-H ambulatory pH monitoring. Am J Gastroenterol 84(12):1503–1508, 1989

    Google Scholar 

  10. Katz PO: Ambulatory esophageal and hypopharyngeal pH monitoring in patients with hoarseness. Am J Gastroenterol 85(1):38–40, 1990

    Google Scholar 

  11. American Thoracic Society: Definitions and classification for chronic bronchitis, asthma and pulmonary emphysema. Am Rev Respir Dir 85:762–768, 1962

    Google Scholar 

  12. Weiner D, Mitra J, Salamone J, Cherniack NS: Effect of chemical stimuli on nerves supplying upper airway muscles. Am Physiol J Appl 52:530–536, 1982

    Google Scholar 

  13. Muers MF: Diurnal variation in asthma. Arch Dis Child 59:898–901, 1984

    Google Scholar 

  14. Werlin SL, Dodds WJ, Hogan WJ, Arndorfer RC: Mechanisms of gastroesophageal reflux in children. J Pediatr 97(2):244–249, 1980

    Google Scholar 

  15. Ducolone A, Vandevenne A, Jouin H, Grob JC, Coumaros D, Meyer C, Burghard G, Methlin G, Hollender L: Gastroesophageal reflux in patients with asthma and chronic bronchitis. Am Rev Respir Dis 135:327–332, 1987

    Google Scholar 

  16. Belsey R: The pulmonary complications of oesophageal disease. Br J Dis Chest 54:342–348, 1960

    Google Scholar 

  17. Sontag S, O'Connell S, Greenlee J, Schnell T, Chintam R, Nemchausky B, Chejfec G, Van Drunen M, Wanner J: Is gastroesophageal reflux a factor in some asthmatics? Am J Gastroenterol 82(2):119–125, 1987

    Google Scholar 

  18. Harper PC, Bergren A, Kaye MD: Anti-reflux treatment in asthma. Improvement in patients with associated gastroesophageal reflux. Ann Intern Med 147:56–60, 1987

    Google Scholar 

  19. Sontag SJ, O'Connell S, Khandelwal S, Miller T, Nemchausky B, Schnell TG, Serlovsky R: Most asthmatics have gastroesophageal reflux with or without bronchodilator therapy. Gastroenterology 99:613–620, 1990

    Google Scholar 

  20. Sontag SJ, Schnell TG, Miller TQ, Khandelwal S, O'Connell S, Chejfec G, Greenlee H, Seidel UJ, Brand L: Prevalence of oesophagitis in asthmatics. Gut 33(7):872–876, 1992

    Google Scholar 

  21. Mittal RK, Lange RC, McCallum RW: Identification and mechanism of delayed esophageal acid clearance in subjects with hiatus hernia. Gastroenterology 92:130–135, 1987

    Google Scholar 

  22. Sloan S, Kahrilas PJ: Impairment of esophageal emptying with hiatal hernia. Gastroenterology 100(3):596–605, 1991

    Google Scholar 

  23. Davis RS, Larsen GL, Grunstein MM: Respiratory response to intraesophageal acid infusion in asthmatic children during sleep. J Allergy Clin Immunol 71:393–398, 1983

    Google Scholar 

  24. Mansfield LE, Stein MR: Gastroesophageal reflux and asthma: a possible reflex mechanism. Ann Allergy 41(4):224–226, 1978

    Google Scholar 

  25. Wright RA, Miller SA, Corsello BF: Acid-induced esophagobronchial-cardiac reflexes in humans. Gastroenterology 99: 71–73, 1990

    Google Scholar 

  26. Mansfield LE, Maneister HH, Spaulding HS, Smith NJ, Glab N: The role of the vagus nerve in airway narrowing caused by intraesophageal hydrochloric acid provocation and esophageal distention. Ann Allergy 47(6):431–434, 1981

    Google Scholar 

  27. Tuchman DN, Boyle JT, Pack AI, Schwartz J, Kokonos M, Spitzer AR, Cohen S: Comparison of airway responses following tracheal or esophageal acidification in the cat. Gastroenterology 87:872–881, 1984

    Google Scholar 

  28. Kennedy JH: “Silent” gastroesophageal reflux: an important but little known cause of pulmonary complications. Dis Chest 42(1):42–45, 1962

    Google Scholar 

  29. Mays EE, Dubois JJ, Hamilton GB: Pulmonary fibrosis associated with tracheobronchial aspiration. Chest 69(4):512–515, 1976

    Google Scholar 

  30. Danus O, Casar C, Larrain A, Pope CE: Esophageal reflux: an unrecognized cause of recurrent obstructive bronchitis in children. 89:220–224, 1976

    Google Scholar 

  31. Euler AR, Byrne WJ, Ament ME, Fonkalsrud EW, Strobel CT, Siegel SC, Katz RM, Rachelefsky GS: Recurrent pulmonary disease in children: a complication of gastroesophageal reflux. Pediatrics 63(1):47–51, 1979

    Google Scholar 

  32. Crausaz FM, Favez G: Aspiration of solid food particles into lungs of patients with gastroesophageal reflux and chronic bronchial disease. Chest 93:376–378, 1988

    Google Scholar 

  33. Shaker R, Ren J, Kern M, Dodds WJ, Hogan WJ, Li Q: Mechanisms of airway protection and UES opening during belching. Am J Physiol (Gastrointest Liver Physiol 25) 262: G621-G628, 1992

    Google Scholar 

  34. Ward PH, Hanson DG: Reflux as an etiological factor of carcinoma of the laryngopharynx. Laryngoscope 98:1195–1199, 1988

    Google Scholar 

  35. Bain WM, Harrington JW, Thomas LE, Schaefer SD: Head andneck manifestations of gastroesophageal reflux. Laryngoscope 93:175–179, 1983

    Google Scholar 

  36. Toohill RJ, Mushtag E, Grossman TW, Lehman RH: Pharyngeal, laryngeal and tracheobronchial manifestations of gastroesophageal reflux. Proc XXIV World Congress of Otolaryngology-Head and Neck Surgery. Berkely, CA: Kugler and Ghedini Publishing, 1994

    Google Scholar 

  37. Cherry J, Margulies SI: Contact ulcer of the larynx. Laryngoscope 78:1937–1940, 1968

    Google Scholar 

  38. Olson NR: The problem of gastroesophageal reflux. Otolaryngol Clin North Am 19:119–133, 1986

    Google Scholar 

  39. Kambic V, Radsel Z: Acid posterior laryngitis. J Laryngol Otol 98:1237–1240, 1984

    Google Scholar 

  40. Ward PH, Berci G: Observations on the pathogenesis of chronic nonspecific pharyngitis and laryngitis. Laryngoscope 92:1377–1382, 1982

    Google Scholar 

  41. Jacob P, Kahrilas PJ, Herzon G: Proximal esophageal pH-metry in patients with ‘reflex laryngitis’. Gastroenterology 100:305–310, 1991

    Google Scholar 

  42. Gabriel CE, Jones DG: The importance of chronic laryngitis. J Laryngol Otol 74:349–357, 1960

    Google Scholar 

  43. Price JC, Jansen CJ, Johns ME: Esophageal reflux and secondary malignant neoplasia at laryngoesophagectomy. Arch Otolaryngol Head Neck Surg 116:163–164, 1990

    Google Scholar 

  44. Shaker R, Dodds WJ, Hogan WJ, Arndorfer R, Hofmann C, Dent J: Mechanisms of esophago-pharyngeal acid regurgitation. Gastroenterology 100(5):A494, 1991

    Google Scholar 

  45. Hersey SJ: Pepsinogen secretion. In: Johnson LR (ed.): Physiology of the Gastrointestinal Tract, 2nd ed. New York: Raven Press, 1987, pp 947–957

    Google Scholar 

  46. Rice DH, Spiro RH: Current Concepts in Head and Neck Cancer. Am Cancer Society, 1989

  47. Cann CI, Fried MP, Rothman KJ: Epidemiology of squamous cell cancer of the head and neck. Otolaryngol Clin North Am 18:367–388, 1985

    Google Scholar 

  48. Wynder EL, Stellman SD: Comparative epidemiology of tobacco-related cancers. Cancer Res 37:4608–4622, 1977

    Google Scholar 

  49. Dennish GW, Castell DO: Inhibitory effect of smoking on the lower esophageal sphincter. N Engl J Med 184:1136–1137, 1971

    Google Scholar 

  50. Kahrilas PJ, Gupta RR: Mechanisms of acid reflux associated with cigarette smoking. Gut 31:4–10, 1990

    Google Scholar 

  51. Stanciu C, Bennett JR: Smoking and gastro-oesophageal reflux. Br Med J 3:793–795, 1972

    Google Scholar 

  52. Burbige EJ, Lewis R, Halsted CH: Alcohol and the gastrointestinal tract. Med Clin North Am 68:77–89, 1984

    Google Scholar 

  53. Pearlman NW, Stiegmann GV, Teter A: Primary upper aerodigestive tract manifestations of gastroesophageal reflux. Am J Gastroenterol 83:22–25, 1988

    Google Scholar 

  54. Mittal RK, Rochester DF, McCallum RW: Sphincteric action of the diaphragm during a relaxed lower esophageal sphincter. Am J Physiol 256:G139-G144, 1989

    Google Scholar 

  55. Mittal RK, Fisher MJ: Electrical and mechanical inhibition of the crutal diaphragm during transient relaxation of the lower esophageal sphincter. Gastroenterology 99:1265–1268, 1990

    Google Scholar 

  56. Dodds WJ, Dent J, Hogan WJ, Helm JF, Patri GK: Mechanisms of gastroesophageal reflux in patients with reflux esophagitis. N Engl J Med 307(25):1547–1552, 1982

    Google Scholar 

  57. Dent J, Holloway RH, Toouli J, Dodds WJ: Mechanisms of lower oesophageal sphincter incompetence in patients with symptomatic gastrooesophageal reflux. Gut 29:1020–1028, 1988

    Google Scholar 

  58. Dent J, Dodds WJ, Friedman RH, Sekiguchi T, Hogan WJ, Arndorfer RC, Petrie DJ: Mechanism of gastroesophageal reflux in recumbent asymptomatic human subjects. J Clin Invest 65:256–267, 1980

    Google Scholar 

  59. Lang IM, Shaker R: An update on the physiology of the components of the upper esophageal sphincter. Dysphagia 9:229–232, 1994

    Google Scholar 

  60. Bonington A, Mahon M, Froes MMQ, Cumming WJK: Histomorphometric and histopathological study of the human cricopharyngeus muscle in man. J Anat 156:27–37, 1988

    Google Scholar 

  61. Kristmundsdottir F, Mahon M, Froes MMQ, Cumming WJK: Histomorphometric and histopathological study of the human cricopharyngeus muscle: in health and in motor neuron disease. Neuropathol Appl Neurobiol 16:461–475, 1990

    Google Scholar 

  62. Doty RW, Bosma JF: An electromyographic analysis of reflex deglutition. J Neurophysiol 19:44–60, 1956

    Google Scholar 

  63. Szentagothai J: Anatomical considerations of monosynaptic reflex arcs. J Neurophysiol 11:445–454, 1948

    Google Scholar 

  64. Goyal RK, Paterson WG: Esophageal motility. In: Wood JD (ed.): Handbook of Physiology: The Gastrointestinal System I. Bethesda, MD: American Physiological Society, 1989, pp 865–908

    Google Scholar 

  65. Venker-van Haagen AJ, Hartman W, Wolvekamp WT: Contributions of the glossopharyngeal nerve and the pharyngeal branch of the vagus nerve to the swallowing process in dogs. Am J Vet Res 47:1300–1307, 1986

    Google Scholar 

  66. Lang IM, Dantas RO, Cook IJ, Dodds WJ: Videoradiographic, manometrica and electromyographic assessment of upper esophageal sphincter function in the dog. Am J Physiol 260:G911-G919, 1991

    Google Scholar 

  67. Asoh R, Goyal RK: Manometry and electromyography of the upper esophageal sphincter in the opossum. Gastroenterology 74:514–520, 1978

    Google Scholar 

  68. Jacob P, Kahrilas PJ, Herzon G, McLaughlin B: Determinants of upper esophageal sphincter pressure in dogs. Am J Physiol 259:G245-G251, 1990

    Google Scholar 

  69. Reynolds RP, Effer GW, Bendel MP. The upper esophageal sphincter in the cat: the role of central innervation assessed by transient vagal blockade. Can J Physiol Pharmacol 1987; 65:96–99

    Google Scholar 

  70. Kahrilas PJ, Dodds WJ, Dent J, Wyman JB, Hogan WJ, Arndorfer RC: Upper esophageal sphincter function during belching. Gastroenterology 91:133–140, 1986

    Google Scholar 

  71. Shaker R, Ren J, Podvrsan B, Dodds WJ, Hogan WJ, Kern M, Hoffmann R, Hintz J: Effect of aging and bolus variables on pharyngeal and upper esophageal sphincter motor function. Am J Physiol 264 (Gastrointest Liver Physiol 27):G427-G432, 1993

    Google Scholar 

  72. Gerhardt DC, Shuck TJ, Bordeaux RA, Winship DH: Human upper esophageal sphincter: response to volume, osmotic, and acid stimuli. Gastroenterology 75(2):268–274, 1978

    Google Scholar 

  73. Gerhardt DC, Castell DO, Winship DH, Shuck TJ: Esophageal dysfunction in esophagopharyngeal regurgitation. Gastroenterology 78:893–897, 1980

    Google Scholar 

  74. Vakil NB, Kahrilas PJ, Dodds WJ, Vanagumas A: Absence of an upper esophageal sphincter response to acid reflux. Am J Gastroenterol 84(6):606–610, 1989

    Google Scholar 

  75. Zamir Z, Shaker R, Boswer M, Dodds WJ, Hogan WJ: Effect of proximal esophageal pH, temperature, and osmolarity on the glottal and UES function. Gastroenterology 102(4):A193, 1992

    Google Scholar 

  76. Kahrilas PJ, Dodds WJ, Dent J, Haeberle B, Hogan WJ, Arndorfer RC: Effect of sleep, spontaneous gastroesophageal reflux, and a meal on upper esophageal sphincter pressure in normal human volunteers. Gastroenterology 92:466–471, 1987

    Google Scholar 

  77. Shaker R, Dodds WJ, Ren J, Hogan WJ, Arndorfer RC: Esophagoglottal closure reflex: a mechanism of airway protection. Gastroenterology 102:857–861, 1992

    Google Scholar 

  78. Shaker R, Ren J, Medda B, Lang I, Cowles V, Jaradeh S: Identification and characterization of the esophagoglottal closure reflex in a feline model. Am J Physiol 266-(Gastrointest Liver Physiol 29):G147-G153, 1994

    Google Scholar 

  79. Wright RA, Miller SA, Corsello BF: Acid-induced esophagobronchial-cardiac reflexes in humans. Gastroenterology 99: 71–73, 1990

    Google Scholar 

  80. Shaker R, Dodds WJ, Dantas RO, Hogan WJ, Arndorfer R: Coordination of deglutitive glottic closure with oropharyngeal swallowing. Gastroenterology 98:1478–1484, 1990

    Google Scholar 

  81. Curtis DJ, Cruess DF, Dachman AH, Maso E: Timing in the normal pharyngeal swallow. Invest Radiol 19:523–529, 1984

    Google Scholar 

  82. Sasaki CT, Isaacson G: Functional anatomy of the larynx. Otolaryngol Clin North Am 21:595–612, 1988

    Google Scholar 

  83. Shaker R, Ren J, Hogan WJ, Liu J, Podvrsan B, Sui Z: Glottal function during postprandial gastroesophageal reflux. Gastroenterology 104(4):A581, 1993

    Google Scholar 

  84. Ren J, Shaker R, Medda B, Bonnevier J, Kern M, Dunn B: Effect of acute esophagitis on the esophagoglottal closure reflex in a feline model. Gastroenterology 108(4):A677, 1995

    Google Scholar 

  85. Meltzer SJ: On the causes of the orderly progress of the peristaltic movements in the oesophagus. Am J Physiol 2:266–272, 1989

    Google Scholar 

  86. Meltzer SJ: Secondary peristalsis of the esophagus—a demonstration on a dog with a permanent esophageal fistula. Proc Soc Exp Biol Med 3:35–37, 1906

    Google Scholar 

  87. Creamer B, Schlegel J: Motor responses of the esophagus to distention. J Appl Physiol 10(3):498–504, 1957

    Google Scholar 

  88. Patterson WG, Hynna-Liepert TT, Selucky M: Comparison of primary and secondary esophageal peristalsis in humans: effect of atropine. Am J Physiol 260:G52-G57, 1991

    Google Scholar 

  89. Williams D, Thompson DG, Heggie L, Bancewicz J: Responses of the human esophagus to experimental intraluminal distension. Am J Physiol 265:G196-G203, 1993

    Google Scholar 

  90. Christensen J: Motor functions of the pharynx and esophagus. In: Johnson LR (ed.): Physiology of the Gastrointestinal Tract, 2nd ed. New York: Raven Press, 1987, pp 595–612

    Google Scholar 

  91. Schoeman MN, Holloway RH: Stimulation and characteristics of secondary oesophageal peristalsis in normal subjects. Gut 35:152–158, 1994

    Google Scholar 

  92. Ren J, Shaker R, Kusano M, Podvrsan B, Metwally N, Dua KS, Sui Z: Effect of aging on the secondary esophageal peristalsis: presbyesophagus revisited. Am J Physiol (Gastrointest Liver Physiol 31) G772–G779, 1995

  93. Soergel KH, Zboralske FF, Amberg JR: Presbyesophagus: esophageal motility in nonagenarians. J Clin Invest 43(7): 1472–1479, 1964

    Google Scholar 

  94. Hollis JB, Castell DO: Esophageal function in elderly men—a new look at “presbyesophagus.” Ann Intern Med 80:371–374, 1974

    Google Scholar 

  95. Paterson WG, Rattan S, Goyal RK: Experimental induction of isolated lower esophageal sphincter relaxation in anesthetized opossums. J Clin Invest 77:1187–1193, 1986

    Google Scholar 

  96. Nishino T, Takizawa K, Yokokawa N, Hiraga K: Depression of the swallowing reflex during sedation and/or relative analgesia produced by inhalation of 50% nitrous oxide in oxygen. Anesthesiology 67:995–998, 1987

    Google Scholar 

  97. Nishino T:Swallowing as a protective reflex for the upper respiratory tract. Anesthesiology 79:588–601, 1993

    Google Scholar 

  98. Shaker R, Ren J, Zamir Z, Sarna A, Liu J, Sui Z: Effect of aging, position, and temperature on the threshold volume triggering pharyngeal swallows. Gastroenterology 107:396–402, 1994

    Google Scholar 

  99. Ebihara T, Sekizawa K, Nakazawa H, Sasaki H: Capsaicin and swallowing reflex. Lancet 341:432, 1993

    Google Scholar 

  100. Christensen J, Lund GF: Esophageal responses to distension and electrical stimulation. J Clin Invest 48:408–419, 1969

    Google Scholar 

  101. Paterson WG: Neuromuscular mechanisms of esophageal responses at and proximal to a distending balloon. Am J Physiol 260(Gastrointest Liver Physiol 23):G148-G155, 1991

    Google Scholar 

  102. Hollshwandner G, Brenman H, Friedman M: Role of afferent sensors in the initiation of swallowing in man. J Dent Res 54:83–88, 1975

    Google Scholar 

  103. Pommerenke W: A study of the sensory areas eliciting the swallowing reflex. Am J Physiol 84:36–41, 1928

    Google Scholar 

  104. Storey A: Interactions of alimentary and upper respiratory tract reflexes. In: Sessle BJ, Hannan AG (eds.). Mastication and Swallowing. Toronto: University of Toronto Press, 1976, pp 22–36

    Google Scholar 

  105. Lichter I, Muir RC: The pattern of swallowing during sleep. Electroencephalogr Clin Neurophysiol 38(4):427–432, 1975

    Google Scholar 

  106. Lear CS, Flanagan JB, Moorrees CF: The frequency of deglutition in man. Arch Oral Biol 10:83–100, 1965

    Google Scholar 

  107. Dent J, Dodds WJ, Friedman RH, Sekiguchi T, Hogan WJ, Arndorfer RC, Petrie DJ: Mechanism of gastroesophageal reflux in recumbent asymptomatic human subjects. J Clin Invest 65:256–267, 1980

    Google Scholar 

  108. Medda BK, Lang IM, Layman R, Hogan WJ, Dodds WJ, Shaker R: Characterization and quantification of a pharyngo-UES contractile reflex in cats. Am J Physiol 167 (Gastrointest Liver Physiol 30):G972-G983, 1994

    Google Scholar 

  109. McClure RC, Dallman MJ, Garrett PG: Cat Anatomy. Philadelphia, PA; Lea and Febiger, 1973

    Google Scholar 

  110. Barlett D: Upper airway motor systems. In: Handbook of Physiology. The Respiratory System. Control of Breathing. Bethesda, MD: 1986, pp 363–394

  111. Ren J, Shaker R, Lang I, Sui Z: Effect of volume, temperature and anesthesia on the pharyngo-UES contractile reflex in humans. Gastroenterology 108(4):A677, 1995

    Google Scholar 

  112. Ren J, Shaker R, Dua K, Trifan A, Podvrsan B, Sui Z: Glottal adduction response to pharyngeal water stimulation: evidence for a pharyngoglottal closure reflex. Gastroenterology 106(42):A558, 1994

    Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Medical College of Wisconsin Dysphagia Institute, Department of Medicine, Medical College of Wisconsin and VA Medical Center, Milwaukee, Wisconsin, USA

    Reza Shaker M.D.

  2. Medical College of Wisconsin Dysphagia Institute, Department of Surgery, Medical College of Wisconsin and VA Medical Center, Milwaukee, Wisconsin, USA

    Reza Shaker M.D.

  3. Medical College of Wisconsin Dysphagia Institute, Department of Radiology, Medical College of Wisconsin and VA Medical Center, Milwaukee, Wisconsin, USA

    Reza Shaker M.D.

Authors
  1. Reza Shaker M.D.
    View author publications

    You can also search for this author in PubMed Google Scholar

Rights and permissions

Reprints and permissions

About this article

Cite this article

Shaker, R. Airway protective mechanisms: Current concepts. Dysphagia 10, 216–227 (1995). https://doi.org/10.1007/BF00431413

Download citation

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00431413

Keywords

Search

Navigation