Ch. 9 Physiology of Mastication and Deglutition

Introductory Terms Dysphagia: A disorder of swallowing Dysphagia: A disorder of swallowing Bolus: ball of food or liquid to be swallowed Bolus: ball of food or liquid to be swallowed Mastication: the process of preparing food for swallowing Mastication: the process of preparing food for swallowing Moving food onto the grinding surfaces of the teethMoving food onto the grinding surfaces of the teeth ChewingChewing mixing it with saliva in preparation for swallowingmixing it with saliva in preparation for swallowing Deglutition: the process of swallowing Deglutition: the process of swallowing Both the two above concepts require integration of lingual, velar, pharyngeal, facial muscle movement, laryngeal adjustments, respiratory controlBoth the two above concepts require integration of lingual, velar, pharyngeal, facial muscle movement, laryngeal adjustments, respiratory control

Introductory Terms Perioral region: around the mouth Perioral region: around the mouth Rooting Reflex: reflexive response of infant to tactile stimulation of the cheek or lips, infant turns toward stimulus, opens mouth Rooting Reflex: reflexive response of infant to tactile stimulation of the cheek or lips, infant turns toward stimulus, opens mouth Sucking Reflex: tongue protrusion and retraction in preparation for receipt of liquid; stimulated by contact to the upper lip Sucking Reflex: tongue protrusion and retraction in preparation for receipt of liquid; stimulated by contact to the upper lip Esophageal Reflux: esophageal regurgitation into the hypopharynx Esophageal Reflux: esophageal regurgitation into the hypopharynx Nasal regurgitation: loss of food or liquid through the nose Nasal regurgitation: loss of food or liquid through the nose Peristaltic: Wavelike Peristaltic: Wavelike

Introductory Terms Oral Transit Time: time required to move the bolus to the point of initiation of the pharyngeal stage of swallowing Oral Transit Time: time required to move the bolus to the point of initiation of the pharyngeal stage of swallowing Pharyngeal Transit Time: time required to move the bolus from the beginning of pharyngeal swallow to the time the bolus enters the esophagus Pharyngeal Transit Time: time required to move the bolus from the beginning of pharyngeal swallow to the time the bolus enters the esophagus

Organizational Patterns Oral Preparatory Stage Oral Preparatory Stage Stage in which food is prepared for swallowStage in which food is prepared for swallow Oral Stage Oral Stage Bolus transmitted to pharynxBolus transmitted to pharynx Pharyngeal Stage Pharyngeal Stage Bolus transmitted to the esophagusBolus transmitted to the esophagus Numerous physiological responsesNumerous physiological responses Esophageal Stage Esophageal Stage Food is transported from the upper esophageal region to the stomachFood is transported from the upper esophageal region to the stomach

Deficit Patterns Oral Preparatory Stage Oral Preparatory Stage Neuromuscular deficitsNeuromuscular deficits Loss of sensation and awareness Loss of sensation and awareness Weak buccal musculature Weak buccal musculature Weak muscles of mastication may cause inadequately chewed food Weak muscles of mastication may cause inadequately chewed food Weak lingual muscles may cause poor mixture of saliva with food, inadequate bolus production, difficulty compressing bolus onto hard palate Weak lingual muscles may cause poor mixture of saliva with food, inadequate bolus production, difficulty compressing bolus onto hard palate Weak soft palate muscles may cause the velum to not be fully depressed, tongue not adequately elevated in back, permitting food to escape into the pharynx prior to initiation of pharyngeal reflexes Weak soft palate muscles may cause the velum to not be fully depressed, tongue not adequately elevated in back, permitting food to escape into the pharynx prior to initiation of pharyngeal reflexes Food entering pharynx prior to a reflexive response may reach the open airway and produce an aspiration pneumonia Food entering pharynx prior to a reflexive response may reach the open airway and produce an aspiration pneumonia

Deficit Patterns Oral Stage Oral Stage Sensory and Motor dysfunctionSensory and Motor dysfunction Weakened movements cause reduced oral transit time, food may remain on tongue and hard palate following transit Weakened movements cause reduced oral transit time, food may remain on tongue and hard palate following transit Epiglottis fail to invert over laryngeal opening, limited elevation of the hyoid, may be increased pooling of food or liquid in the valleculae Epiglottis fail to invert over laryngeal opening, limited elevation of the hyoid, may be increased pooling of food or liquid in the valleculae Difficulty initiating a reflexive swallow may be due to a sensory deficit Difficulty initiating a reflexive swallow may be due to a sensory deficit

Deficit Patterns Pharyngeal Stage Pharyngeal Stage Sensory and Motor DysfunctionSensory and Motor Dysfunction Slow velar elevation may result in nasal regurgitation Slow velar elevation may result in nasal regurgitation Reduced sensation of fauces, posterior tongue, pharyngeal wall, soft palate may cause elevated threshold for trigger of swallowing reflex Reduced sensation of fauces, posterior tongue, pharyngeal wall, soft palate may cause elevated threshold for trigger of swallowing reflex Reduced function of pharyngeal constrictors may result in slowed pharyngeal transit time of bolus and individual may reinitiate respiration Reduced function of pharyngeal constrictors may result in slowed pharyngeal transit time of bolus and individual may reinitiate respiration Weakened pharyngeal function may result in residue left in the valleculae Weakened pharyngeal function may result in residue left in the valleculae Failure of the hyoid and thyroid to elevate may result in loss of airway protection, food may fall into larynx and be aspirated on breathing Failure of the hyoid and thyroid to elevate may result in loss of airway protection, food may fall into larynx and be aspirated on breathing

Deficit Patterns Esophageal Stage Esophageal Stage GERD: acids from the stomach flow to the esophagus and pharynx, may be UES or LES problem or bothGERD: acids from the stomach flow to the esophagus and pharynx, may be UES or LES problem or both Hiatal Hernia: LES may malfunction allowing reflux into esophagusHiatal Hernia: LES may malfunction allowing reflux into esophagus Congenital Malformation: stenosis, see figure 9-4Congenital Malformation: stenosis, see figure 9-4

Neurophysiology Gustation Gustation Taste mediated by 3 cranial nervesTaste mediated by 3 cranial nerves V!! mediates sense of taste from anterior 2/3 of the tongue, sweet and sour sensations, and of palate. Sides transmit salt and sour. V!! mediates sense of taste from anterior 2/3 of the tongue, sweet and sour sensations, and of palate. Sides transmit salt and sour. IX mediates sense of taste, primarily of bitterness from posterior 1/3 of tongue. Sides transmit salt and sour IX mediates sense of taste, primarily of bitterness from posterior 1/3 of tongue. Sides transmit salt and sour X mediates sense of taste from epiglottis and esophagus X mediates sense of taste from epiglottis and esophagus Umami: taste receptor which processes monosodium glutamate. Umami: taste receptor which processes monosodium glutamate.

Neurophysiology Gustation Gustation Tastes, bitter and sour may typify poison and elicit a protective response Tastes, bitter and sour may typify poison and elicit a protective response GaggingGagging CoughingCoughing ApneaApnea Salivation (encapsulates the material and protects the oral cavitySalivation (encapsulates the material and protects the oral cavity

Neurophysiology Gustation Gustation Taste can elicit motor responses that may or may not be under volitional control Taste can elicit motor responses that may or may not be under volitional control Gag responseGag response Elevation of the larynx Elevation of the larynx Clamping of the vocal folds Clamping of the vocal folds Elevation of the velum Elevation of the velum Protrusion of the tongue Protrusion of the tongue

Neurophysiology Gustation Gustation Taste can elicit motor responses that may or may not be under volitional control Taste can elicit motor responses that may or may not be under volitional control CoughingCoughing Tightly closing VF and supraglottic structures Tightly closing VF and supraglottic structures Compressing of abdomen and thorax Compressing of abdomen and thorax Forcefully blowing VF apart Forcefully blowing VF apart

Neurophysiology Olfaction Olfaction Olfactory chemoreceptors in nasal mucus membraneOlfactory chemoreceptors in nasal mucus membrane Sense of smell transmitted to olfactory bulb in cranial spaceSense of smell transmitted to olfactory bulb in cranial space

Neurophysiology Tactile Sense Tactile Sense In face and oral cavity, primarily mediated by V, but IX and X are associatedIn face and oral cavity, primarily mediated by V, but IX and X are associated

Neurophysiology Thermal Receptors Thermal Receptors In face and oral cavity, primarily mediated by V, but IX and X are associatedIn face and oral cavity, primarily mediated by V, but IX and X are associated Same as pain sensors, bare nerve endingsSame as pain sensors, bare nerve endings Differentiate warm, hot, cool, cold: receptors are tuned to particular temperaturesDifferentiate warm, hot, cool, cold: receptors are tuned to particular temperatures

Neurophysiology Muscle stretch and Tension sense Muscle stretch and Tension sense In face and oral cavity, primarily mediated by V, but IX and X are associatedIn face and oral cavity, primarily mediated by V, but IX and X are associated