Typical Swallowing Events

Soft Palate: The posterior part of the roof of the mouth, separates the nasal passages from the oral cavity during swallowing.
Hard Palate: The bony front part of the roof of the mouth, plays a role in the shaping and control of the bolus.
Tongue: Primarily responsible for moving the food bolus into the oropharynx.
Hyoid Bone: Small U-shaped bone in the neck, important for the movement of the larynx during the swallowing process.
Nasopharynx: The upper part of the pharynx, lying above the soft palate, important for airflow and preventing nasal regurgitation.
Oropharynx: The portion of the pharynx located behind the oral cavity, serves as a pathway for food.
Thyroid Cartilage: A component of the larynx, provides structure and support.
Vocal Folds: Structures within the larynx that help prevent food and liquid from entering the airway during swallowing.
Larynx: Voice box that plays an important role in airway protection.
Cricoid Cartilage: A ring-shaped cartilage that forms the lower part of the larynx.
Thyroid Gland: An endocrine gland located in the neck, not directly involved in swallowing but may affect muscle actions.
Laryngopharynx: The lower part of the pharynx, directing food into the esophagus.
Upper Esophageal Sphincter (UES): The muscle that separates the esophagus from the pharynx, allows the bolus to enter the esophagus.
Esophagus: The tube that carries food from the throat to the stomach.

Bolus Efficiency:
- Objective: Move the ingested bolus into the esophagus in a timely manner without significant residue, effort, or need for repeated swallows.
Airway Protection:
- Objective: Prevent ingested materials from entering the larynx and/or trachea during the swallowing process.

Posterior Lingual Propulsion: The quick and forceful movement of the tongue that pushes the bolus back into the pharynx.
Swallow Trigger: Sensory stimulation initiates the swallowing reflex in the oropharyngeal region.
Velar Elevation: The soft palate elevates to prevent nasal regurgitation and help create downward pressure on the bolus.
Laryngeal Vestibule Closure: Acts as the first line of defense for airway protection during swallowing.
Pharyngeal Constriction & Elevation: Involves contraction of pharyngeal muscles to help propel the bolus downward.
UES Opening: Opening of the UES allows the bolus to move from pharynx to esophagus, ensuring efficient passage.

Definition and Role:
- A rapid and forceful movement of the tongue that propels the bolus posteriorly into the pharynx. This event is crucial for the containment of the bolus as it moves in an anterior-posterior (AP) direction. The bolus is pushed against the hard palate while being contained by the mid-tongue.

Trigger Definition:
- The swallowing process is initiated by sensory stimulation of the oropharyngeal region, which can vary among individuals. This trigger is essential as it marks the onset of all subsequent swallowing events and plays a role in both bolus efficiency and airway protection.

Mechanism:
- The soft palate elevates in a posterior direction and makes contact with the posterior pharyngeal wall. This action aims to prevent any nasal regurgitation of the bolus while simultaneously building downward pressure on it.

Importance:
- Functions as the primary defense for the airway during the act of swallowing. The closure involves multiple components, including:
- Hyolaryngeal Excursion:
- The hyoid bone and larynx move upward and forward. This activity positions the epiglottis higher and provides traction on the UES to stretch and open it.
- Arytenoid Adduction and Forward Movement:
- At rest, the arytenoids are spaced further apart. During swallowing, they come together (adducted) and pivot anteriorly toward the base of the epiglottis, preventing penetration of food into the airway.
- Aryepiglottic Fold Bunching:
- The folds stand upright at rest and bunch together as the epiglottis inverts and the arytenoids adduct and pivot. This bunching action aids in preventing aspiration as the bolus moves laterally along both sides of the larynx.
- Epiglottic Inversion:
- The base of the tongue passively helps in moving the epiglottis while the pharyngeal constriction actively assists in positioning the epiglottis into an inverted position.

Mechanism Description:
- This involves sequential innervation of the constrictor muscles and elevation through the innervation of the longitudinal muscles. Pharyngeal constriction aids in epiglottic inversion, which is crucial for airway protection.

Functionality:
- The UES opens to permit the bolus to pass from the pharynx into the esophagus. This occurs through the relaxation of sphincter muscles, aided by laryngeal excursion. However, if there is impaired UES opening, it could lead to secondary aspiration after the swallow because the bolus may remain in the pharynx.

Both airway protection and bolus efficiency are prioritized during swallowing, with most swallowing events contributing to one or both of these goals.

Sue has oral residue after swallowing. What swallowing event(s) may be impacted leading to this residue? Which muscles/groups might be involved?

In the VFSS of a patient, if the bolus remains above the vocal folds and clears during swallowing, what mechanisms or events deviated from the typical process? How did this occur, and was there any penetration or aspiration?

Bob's swallowing event triggers at the level of the pyriform sinuses. Is this considered a delayed swallow? What could be the potential consequences of this delayed trigger?