A&P Swallowing (Mastication and Deglutition)

Pharyngeal Phases (6) 3. Closure of larynx

*( false folds, true folds, aryepiglottic contraction, arytenoid tilting, epiglottis inversion)* • prevents material from entering trachea a) lateral cricoarytenoid - adducts vocal folds b) transverse arytenoid - adducts vocal folds c) oblique arytenoid - adducts vocal folds *(ALL ADUCT VOCAL FOLDS)*

Oral Phase: Tongue propels bolus posteriorly (to faucial pillars)

*(all extrinsic tongue muscles + 1 intrinsic)* a) mylohyoid • elevate tongue & floor of mouth b) superior longitudinal • elevate tip c) genioglossus • moves & cups tongue body d) styloglossus • elevates, retracts posterior tongue e) palatoglossus • elevates posterior tongue *(tongue activated during transfer)*

Pharyngeal Phases (6) 1. Velopharyngeal closure

*(prevents food or liquid from entering nasal cavity)* a) levator veli palatini • elevates soft palate b) tensor veli palatini • tenses palate c) musculus uvulae • shortens soft palate

Oral Phase: Mandibular Muscles (7)

*Elevate* a) masseter • elevate mandible b) temporalis • elevate, retract, protrude mandible c) medial pterygoid • elevate mandible, grinding *Depressors* d) lateral pterygoid • protrudes, depresses mandible, grinding e) mylohyoid • depress mandible f) geniohyoid • depress mandible g) digastric • depress mandible

Oral Phase: Tongue Muscles (8)

*Intrinsic* a) superior longitudinal • elevate & deviate tip b)inferior longitudinal • depress & deviate tip c) transverse • narrows, elongates tongue d) vertical • flattens, widens tongue *Extrinsic* e) genioglossus • moves & cups tongue body f) hyoglossus • depress & retract tongue g) styloglossus • elevates posterior tongue h) palatoglossus • elevates posterior tongue

How/What muscles are involved with mastication & deglutition

*• 55 muscle pairs involved* - lips/face: lip opening/seal, cheek compression - jaw: open/close; mastication - tongue: internal & external for manipulating food - velum: close off nasal cavity (so stuff doesn't come out) - larynx: close off airway - pharynx: propel food down to esophagus *(tongue is very active)* *(chewing is a grinding motion) (compression in cheeks while chewing)*

What are the 3 phases of swallowing?

1) Oral phase 2) Pharyngeal phase 3) Esophageal phase

Pharyngeal Phases (6)

1) Velopharyngeal closure 2) Superior & anterior movement of the hyoid & larynx 3) Closure of larynx 4) Base of tongue retraction 5) progressive superior → inferior constriction of pharyngeal muscles 6) opening of the UES

Anatomy: Larynx

a) Aryepiglottic folds/epiglottis (form laryngeal wall) - form the lateral walls of the laryngeal vestibule - pyriform sinuses (space between aryepiglottic fold & thyroid cartilage) b) False vocal folds c) True vocal folds d) Protection of the airway from entry of material • True vocal fold closure (phonation) • False vocal fold closure • Arytenoids tilting (to make true vf come together) • Aryepiglottic folds contraction • Epiglottis inversion (inverts & covers for further protection of airway) *(biological function of laryngeal system PROTECTION)*

Anatomy: Pharynx

a) Pharyngeal Recesses (cavity in pharyngeal region) • *Valleculae* - Space between the base of tongue anteriorly & epiglottis posteriorly - Divided by the hyoepiglottic ligament • *Pyriform sinuses* - Space between the thyroid cartilage (laterally) and aryepiglottic folds (medially) • Material can collect in one or both spaces before or after the swallow *(food & liquids should NOT stay in valleculae)* *(to much residue in area causes problems)*

Oral Phase: Velum

a) Remains depressed b) Open velopharyngeal port: • Glossopalatal seal

Oral Phase: Mastication ceases

a) masseter • elevate mandible b) temporalis • elevate mandible c) medial pterygoid • elevate mandible

Oral Phase: Facial Muscles

a) orbicularis oris (helps form seal) • oral seal b) mentalis (swallowing & closing mouth off) • elevate lower lip c) buccinator, risorius • flatten cheek (pockets happen left over food in cheeks)

What are the 4 different stages?

stage 1 = preparation stage 2 = transfer stage 3 = pharyngeal stage 4 = esophagus

Oral Phase: Transfer

• *Beginning:* initiated with onset of bolus movement • *End:* bolus reaches angle of mandible (may be sooner depending on onset of hyoid and laryngeal elevation to maximum) *(transfer = moving stuff from front to back in oral cavity)*

Esophageal Phase

• Bolus travels through esophagus • Peristalsis - Contraction of the muscle segment behind the bolus & relaxation of the muscle segment in front of the bolus - moves bolus through esophagus down to stomach • Beginning: bolus enters esophagus • End: bolus enters stomach via lower esophageal sphincter

Pharyngeal Phases (6) 4. Base of tongue retraction

• Continuous movement of tongue after passage of bolus • Anterior bulging of superior posterior pharyngeal wall - Superior pharyngeal constrictor • Provides pressure to drive bolus through pharynx a) genioglossus • retract tongue b) styloglossus • elevate, retracts posterior tongue c) palatoglossus • narrows faucial arches; elevates posterior tongue *(provides closure & allows pressure build up to push stuff back)*

Pharyngeal Phases (6) 6. opening of the UES

• Cricopharyngeus muscle relaxes (otherwise contracted) • Anterior movement of hyoid and larynx - Geniohyoid: (2) 1. Anterior digastric 2. Mylohyoid *(allows a little more space)*

Anatomy: Esophagus part 1

• Esophagus a) Long collapsed muscular tube runs from the pharynx to the stomach (posterior it tracheal system) b) Bounded by contracted muscles: 1• Upper Esophageal Sphincter (UES) - Pharyngoesophageal segment (PES) 2• Lower Esophageal Sphincter (LES) *(between esophagus & stomach)* c) 22-26 cm in length *(sphincters approx 2 cm in length)* d) Upper 1/3 of esophagus is *striated* muscle e) Lower 2/3 of esophagus is *smooth* muscle

Pharyngeal Phases (6) 2. Superior & anterior movement of the hyoid & larynx

• Facilitates airway protection • Anterior movement allows for opening of UES • Moves hyoid and larynx superiorly and anteriorly - anterior belly of digastric - mylohyoid - geniohyoid - thyrohyoid *(UES = Upper Esophageal Sphincter)*

Oral Phase: Preparation

• Food prepared for swallow - Food is manipulated & chewed (masticated) - Mixed with saliva - Prepared to a consistency suitable for swallowing - Liquid versus solid • *Begins:* food enters mouth • *Ends:* bolus is formed

Mastication and Deglutition

• Manipulation and/or mastication of material (bolus) in the oral cavity • Transport through the oral cavity • Elicitation of the pharyngeal swallow • Transfer through pharynx • Transfer through esophagus into stomach *(have to be able to chew to form bolus)*

Pharyngeal Phase

• Patterned response - Central pattern generator in medulla - Influence from cortical & subcortical regions - Patterned response allows for modification of behavior • *Beginning:* Onset of pharyngeal swallow • *End:* tail of bolus enters esophagus

Physiology of Normal Swallowing

• Three phases of deglutition-highly integrated 1) Oral phase-volitional (complete control) • Oral preparation • Oral transfer 2) Pharyngeal phase-patterned response 3) Esophageal phase-reflexive

Onset of the Pharyngeal Swallow

• Transition from the oral stage and the pharyngeal stage • *Beginning:* Head of bolus reaches mandibular angle (can be normal variations) • *End:* Onset of hyoid and laryngeal elevation toward maximum

Anatomy: Esophagus part 2

• UES (must be relaxed for food to go down) - Two processes to open 1) Relaxation of the cricopharyngeus muscle 2) Anterior movement of the hyoid and larynx • Esophageal disorders - generally addressed by gastroenterologists (not SLPs) • BUT, esophageal disorders can impact the pharynx and vice versa

Anatomy & Physiology of Swallowing

• Upper Aero-digestive tract (dual purpose) - oral cavity - nasal cavity (air only) - pharynx - larynx - cervical esophagus • System alternates between a breathing tube & a swallowing tube *(acts for breathing & swallowing)*

Oral Phase: Prep

• Velum - At rest; lowered position - Velopharyngeal port open • Teeth: chewing

Pharyngeal Phases (6) 5. progressive superior → inferior constriction of pharyngeal muscles

• bolus splits, moves around larynx via pyriform sinuses, then re-joins to enter esophagus a) palatopharyngeus • constricts oropharynx to channel bolus to esophagus b) salpingopharyngeus • elevates pharynx (pharyngeal shortening) c) superior constrictor • narrows pharynx d) middle constrictor • narrows pharynx e) inferior constrictor • narrows pharynx *(most important muscle superior, middle, & inferior constrictors)* *(squeeze, open, squeeze, open motion)*