The Normal Swallow (view MBS) - PowerPoint Presentation

1. The Normal Swallow(view MBS)Bonnie Martin-Harris MUSC

2. 3 Stages or phases of swallowingSwallowingOne continuous act Can be divided into 3 interdependent stages (Logemann)Oral (includes oral/preparatory as discussed in Logemann)PharyngealEsophageal

3. MBSImp(Martin-Harris et al. 2008, 2010)Standardized measurement tool for interpreting MBSNo stages Reported asOral impairmentPharyngeal impairmentEsophageal impairmentMoving Toward Standardizing DysphagiaPractice: Introducing The Modified BariumSwallow Impairment Profile (MBSImP)http://www.northernspeech.com/seminar_detail/1000118/Assessment_Tests__Screening_Tools/1001231/The_Modified_Barium_Swallow_Impairment__Profile_MBSImP__A_Standardized_Assessment_and_Treatment__Planning_Protocol/

4. http://www.radiologyassistant.nl/images/thmb_44297df2c4541oral1+2.jpgFood enters mouth Lip closure Tongue gathers bolusOral observations

5. Oral/preparatorystage descriptionPreparation of food boluses in the oral cavityEnds when the bolus is gathered into a cohesive unitBefore the swallowing responseTongue moves bolus laterallyChewing (first stage of deglutition) reduces bolus sizeTongue dorsum elevation prevents liquid and solids from prematurely entering the airway

6. Oral/preparatory stage musclesPaired muscles used in chewingTemporalis -CN V (trigeminal)Masseter -CN V (trigeminal)Buccinator -CN V (trigeminal)Pterygoid -CN V (trigeminal)

7. Oral/preparatory stage soft tissueLipsTongueCheeksSulciSalivary glands

8. TongueTipBladeDorsumRoot or base of tongue (BOT)Median groove or central groovePapillae

9. Salivary glandshttp://www.entnet.org/healthinfo/throat/salivary.cfmParotidSerous fluidThinnerMore waterySubmandibularMostly serous fluidSome mucusSublingualMostly mucusSome serous

10. Parotid gland tumorParotid gland produces serous fluidhttp://www.ghorayeb.com/ParotidCyst.html

11. Function of salivaMaintain oral moistureReduce tooth decayAssist in digestionNatural neutralizer of stomach acid from esophageal refluxProduction of saliva is triggered by chewing

12. Oral/preparatory stage nervesSalivary glands innervation (sensory)CN VII (facial)-sublingual and submandibularCN IX (glossopharyngeal)-parotidTongue, teeth, gums, palate (sensory)CN V (trigeminal) –mechanical pressure sensorsCN V (trigeminal) –change in temperatureCN VII (facial) –chemo-receptors for tasteanterior 2/3 of tongueCN IX (glossopharyngeal) –chemo-receptors for tasteposterior 1/3 of tongue

13. Oral/preparatory stage central controlHigher cortical centersCapable of initiating and terminating a swallowMedulla (brainstem)Nucleus tractus solitarius (NTS) Receives information from sensory branches of CNTasteTemperatureMastication

14. Oral stage - a.k.a. oral pharyngeal stagehttp://www.radiologyassistant.nl/images/thmb_44297df2c4541oral1+2.jpgSoft palate closes off nasal cavityTongue propels bolus backHyoid bone begins to move up and forward

15. Oral stage descriptionBegins after the bolus is gathered and prepared for swallowingTongue cradles bolusPresses edges against hard palateTongue propels bolus posteriorlyPosterior pharyngeal wall moves anteriorlyHyoid bone begins to elevate and move anteriorlyVelum elevatesAirway begins to close

16. Oral stage nerves & musclesTongue –Extrinsic tongue muscles cradle bolusGenioglossus (CN XII Hypoglossal)comes from the genial tubercule of the mandiblecomprises most of the bulk of the tongue. Hyoglossus (CN XII Hypoglossal)attached to the hyoid bone Styloglossus (CN XII Hypoglossal) comes from the styloid process of the temporal bone Palatoglossus (CN XI Accessory & CN X Vagus) connects the soft palate to the tongueforms the bulk of the anterior of two arches that delineate the oral cavity from the oropharynx.

17. http://en.wikipedia.org/wiki/File:Gray1019.png

18. Oral stage nerves & musclesTongue –Extrinsic tongue muscles propel bolus posteriorlyDigastric (CN V Trigeminal)Myohyoid (CN V Trigeminal)Geniohyoid (CN XII Hypoglossal)

19. http://en.wikipedia.org/wiki/File:Gray1019.png

20. Oral stage nerves & musclesTongue –Posterior elevated Palatoglossus (CN X Vagus)Velum elevationPalatopharyngeal (CN X Vagus & CN XI Accessory)Levator veli palatini (CN X Vagus & CN XI Accessory)Tensor veli palatini (CN V Trigeminal)

21. Oral stage nerves & musclesFalse and true vocal folds -airway closure (motor)CN X Vagus recurrent branchMechanical, chemical, and water respondent receptors (sensory)CN X Vagus superior laryngeal nerve

22. http://images.google.com/imgres?imgurl=http://www.radiologyassistant.nl/images/thmb_44299de5ccc67pharyngeal1%2B2.jpg&imgrefurl=http://www.radiologyassistant.nl/en/440bca82f1b77&h=205&w=370&sz=24&hl=en&start=73&um=1&tbnid=XtdH_wPZMkUptM:&tbnh=68&tbnw=122&prev=/images%3Fq%3Dpharyngeal%2Bstage%26start%3D72%26ndsp%3D18%26um%3D1%26hl%3Den%26rlz%3D1T4GGLR_enUS247US248%26sa%3DNMaintained elevationPharynx shortensLarynx raises 2-3 cmEpiglottis partially covers airwayUES opensTrigger ptPharyngeal stage

23. Pharyngeal stage descriptionBegins when bolus passes the trigger point (arbitrary location) and enters pharynx Velum remains elevated, airway remains closedHyoid bone elevation and anterior position maintainedPharynx shortensLarynx moves up (2-3 cm) under tongueEpiglottis folds down over airwayUES opens

24. Pharyngeal stage nerves & musclesElevate and shorten pharynx as bolus arrivesPalatopharyngeal (CN X Vagus & CN XI Accessory)pulls the walls of the pharynx superiorly, anteriorly and medially during swallowing Stylopharyngeus (CN IX Glossopharyngeal)

25. Pharyngeal stage nerves & musclesFalse and true vocal folds -airway closureShould occur during oral/pharyngeal stage but reported as pharyngeal stageCN X Vagus recurrent branch

26. Pharyngeal stage nerves & musclesRelax during swallowForm outer layer of theanterior wall of pharynx Posterior pharyngeal wall moves anteriorlySuperior constrictor (CN X Vagus & CN XI Accessory)Middle constrictor (CN X Vagus)Inferior constrictor (CN X Vagus & CN XI Accessory)http://www.emory.edu/ANATOMY/AnatomyManual/pharynx.html

27. Inferior constrictor muscleRelaxes during swallowTwo partsThyropharyngeusCricopharyngeus (AKA Upper esophageal sphincter or UES)

28. Esophageal stagehttp://www.radiologyassistant.nl/en/472458f15c55a

29. Esophageal descriptionAt rest esophagusClosed muscular tube18-22 cm (8-10 inches)Enters stomach through the diaphragmatic hiatusUES-superior boundaryLower esophageal sphincter (LES)-inferior boundary

30. Peristalsis delivers bolus from proximal to distal esophagus (3-10 sec)First contractile wave is strongestMore efficient the pharyngeal clearance the stronger the waveMultiple swallows of the same bolus may inhibit peristalsisSecondary peristaltic wave signals LES to openEsophageal stage description

31. Esophageal stage nerves and musclesEsophagusUpper 1/3 is striated muscleCN X Vagus from nucleus ambiguusMiddle 1/3 mixed striated and smooth muscleLower 1/3 is smooth muscleCN X Vagus from dorsal motor nucleus

32. Normal swallow

33. Central control of swallow“Swallow Center” (NTS+NA)Located in the medulla of the brainstemNTS (Nucleus tractus solaritus or nucleus of the solitary tract )Integrates sensory info of touch, sense, tasteAfferent input from CN V, VII, IX, XAfferent input from cardiovascular and respiratory brainstem nucleiTransfers sensory information to NA

34. Central control of swallowNA (Nucleus ambiguus)Integrates and coordinates motor output to the swallowing musclesVia CN V, VII, IX, X, XI, XII

35. Central control of swallowNTS communicates withHypothalamusHunger and thirstSensory motor strip in parietal lobePrecentral cortexLateral postcentral gyrusSupplementary motor areaLimbic forebrainCerebellum

36. Rapid transfer of the bolus in a normal swallowOral cavity to pharynx (liquids).05-1 secondOral cavity to stomach (liquids)<5 secondsHigh pressure on bolusNegative pressure below level of bolusEsophagus remains (-) pressure

37. Creating zones of high and low pressureAccomplished by coordination and strength of swallowing valves.

38. ValvesLipsClosure builds intraoral pressureVelumSeals nasopharynx from foreign matterTongue dorsumSeals oral cavity from pharyngeal reflux during swallowFalse vocal folds (vf)Protects airway

39. ValvesTrue vocal foldsProtects airwayUpper esophageal sphincter (UES) a.k.a. pharynoesophageal (PES) or cricopharyngeus (CP)Relaxes for bolus entryCloses to avoid regurgitationLower esophageal sphincter (LES)Relaxes for bolus entryCloses to avoid refluxCricopharyngeal achalasia (abnormal)

40. Mechanism of UES openingMechanical tractionPosterior tongue retractionHyoid bone elevationHyoid bone elevates the thyroid and cricoid cartilagesBolusDrivingforceBrainstemdisinhibition

41. Mechanisms of airway protection during swallowingAirway closureTrue and false vocal folds adductLaryngeal aditus narrowsLaryngeal elevationLarynx raises and tilts under base of tongueTongue base retractionPosterior tongue action deflects bolus away from airway

42. Mechanisms of airway protection during swallowing3. Epiglottis invertsRising larynx and thyroepiglottic ligament contraction allows epiglottis to fold over the laryngeal aditus4. Vallecular spacesBolus divided and channeled around airway

43. Valves create a series of positive and negative pressuresPharyngeal phaseTongue base & pharyngeal constrictors(+) pressure on bolus as it flows into (-) pressure in pharynx(-) pressure aids in UES openingEsophageal phasePeristalsis applies (+) pressureEsophagus is a (-) pressure structureThe bolus is both pressed down by peristalsis and sucked down via (-) pressure

44. Respiration and Swallowing

45. Apneic periodAirway closure periodNo respirationDuration increases as bolus volume increases75% of normal swallows begin with exhalation and typically followed by continued exhalationDysphagic pts more likely interrupt inhalation to swallow

46. Variations in Normal Swallow

47. Volume effectsLarger bolus volumes preceded by inhalationSmall bolus (5 ml) Oral phase followed by pharyngeal phaseLarge bolus (10-20 ml) Simultaneous oral and pharyngeal phasesNeeded to safely clear bolusTongue base and pharyngeal wall movement occurs later

48. Increase in viscosityPressure of tongue and pharyngeal walls increaseValve functions increase in durationVelar closureLaryngeal closureUES opening

49. Swallow ReviewAll normal swallows includeOral propulsion of the bolus into the pharynxAirway closurePES/UES openingTongue base-pharyngeal wall propulsion to move bolus from pharynx into the esophagus