Physiology of Mastication & Swallowing – Key Vocabulary

Comprehensive vocabulary flashcards highlighting major terms, structures, reflexes, sensory systems, stages, disorders, and assessments associated with mastication and swallowing physiology.

Mastication

Medical term for chewing; the mechanical breakdown and mixing of food in the oral cavity.

Deglutition

The entire act of swallowing, from bolus preparation through esophageal passage.

Bolus

Any liquid or solid material in the mouth that is being prepared for swallowing.

Clinical Swallow Evaluation (Bedside)

Subjective, non-instrumental assessment of swallowing performed by an SLP at bedside or clinic.

Instrumental Study

Objective imaging assessment (e.g., FEES or MBSS) that visualizes anatomic and physiologic aspects of swallowing.

FEES (Fiberoptic Endoscopic Evaluation of Swallowing)

Endoscopic swallow study using a transnasal scope to visualize pharyngeal/laryngeal structures from above.

MBSS (Modified Barium Swallow Study)

X-ray (fluoroscopic) swallow exam in which barium-coated materials are ingested to view all stages side-on.

VFSS (Videofluoroscopic Swallow Study)

Synonym for MBSS; dynamic X-ray imaging of swallowing.

PO Trials

Presentation of food or liquid by mouth during an evaluation to observe swallowing function.

Aspiration

Entry of material below the level of the true vocal folds into the airway.

Silent Aspiration

Aspiration without overt signs such as cough or throat clearing.

Oral Preparatory Stage

First stage of swallowing in which food is chewed, mixed with saliva, and formed into a cohesive bolus.

Oral Transport (Oral Propulsive) Stage

Second stage where the tongue propels the bolus posteriorly toward the oropharynx.

Pharyngeal Stage

Third, involuntary stage beginning at the faucial pillars; bolus is transported through the pharynx while airway is protected.

Esophageal Stage

Fourth reflexive stage in which peristalsis moves the bolus from UES to LES and into the stomach.

Upper Esophageal Sphincter (UES)

Cricopharyngeal region that relaxes to allow bolus entry into the esophagus.

Lower Esophageal Sphincter (LES)

Distal esophageal sphincter that opens to permit entry into the stomach and closes to prevent reflux.

Peristalsis

Wave-like contraction of smooth muscle that propels the bolus through the esophagus.

Airway Protection

Series of events (laryngeal elevation, epiglottic inversion, VF adduction) preventing bolus entry into the airway.

Epiglottis

Leaf-shaped cartilage that retroflexes over the laryngeal inlet during swallowing.

Orbicularis Oris

Facial muscle that seals the lips during oral prep and transport.

Masseter

Primary mandibular elevator used in chewing.

Soft Palate (Velum)

Muscular palate that elevates to block the nasopharynx during swallowing.

Parotid Gland

Major salivary gland located anterior to the ear; secretes saliva near upper second molar.

Submandibular Gland

Walnut-sized salivary gland under the jaw; empties under the tongue.

Sublingual Gland

Smallest major salivary gland; almond-shaped, beneath the oral floor.

Salivation

Motor response releasing saliva into the oral cavity, stimulated by sight, smell, or taste.

Mechanoreceptors

Sensory receptors in tongue and palate conveying bolus size, texture, and cohesion.

Chemoreceptors

Receptors responding to chemical composition (taste, O2/CO2) aiding swallow initiation.

Thermoreceptors

Temperature-sensitive receptors providing hot/cold information about the bolus.

Filiform Papillae

Most numerous papillae; provide tactile information, no taste buds.

Fungiform Papillae

Taste and tactile papillae on anterior two-thirds of tongue (sweet, salty).

Circumvallate Papillae

Large papillae forming a V near tongue root; taste buds for bitter on posterior tongue.

Foliate Papillae

Leaf-shaped papillae on posterolateral tongue edges; contain taste buds (sour).

Olfaction

Sense of smell; closely linked to appetite and flavor perception.

Central Pattern Generator (CPG)

Brainstem network that produces rhythmic chew and swallow sequences without cortical input.

Rooting Reflex

Infant reflex turning head and opening mouth toward cheek/lip stimulation (diminishes 3–4 mo).

Suckling Reflex

Primitive front-to-back tongue movement allowing milk extraction; integrates 6–12 mo.

Sucking Reflex

More mature up-and-down tongue/lip action for efficient feeding; established ~4 mo.

Chewing Reflex

Automatic rotary jaw movement triggered by deep palate pressure; midbrain mediated.

Palatal (Gag) Reflex

Protective elevation/constriction of pharynx in response to posterior oral stimulation.

Cough Reflex

Forceful expiratory response to noxious airway stimuli; clears material from airway.

Nasal Regurgitation

Backflow of bolus into nasopharynx due to velopharyngeal incompetence.

Pharyngeal Transit Time

Duration of bolus passage through pharynx; prolonged time increases residue risk.

Retrograde Aspiration

Aspiration of material that refluxes upward from esophagus or pharynx.

Gastroesophageal Reflux Disease (GERD)

Return of gastric contents into esophagus/pharynx due to LES dysfunction.

Esophageal Stenosis

Abnormal narrowing of the esophageal lumen, often treated with balloon dilation.

Tracheoesophageal Fistula

Abnormal connection between trachea and esophagus that allows food/air cross flow.

Brainstem

Central ‘swallow center’ housing sensory nuclei, CPGs, and cranial nerve origins critical for swallowing.

Solitary Tract Nucleus (NST)

Brainstem nucleus receiving taste and visceral sensory input for swallow control.

Dorsal Swallowing Group

Brainstem region coordinating sequential motor commands for the swallow reflex.

Trigeminal Nerve (CN V)

Provides oral touch/pressure/temperature sensation; motor to muscles of mastication.

Facial Nerve (CN VII)

Conveys anterior tongue taste; motor to lips/cheeks; stimulates salivary glands.

Glossopharyngeal Nerve (CN IX)

Carries posterior tongue taste, pharyngeal sensation; assists in swallow reflex.

Vagus Nerve (CN X)

Supplies laryngeal/pharyngeal motor and sensory functions; key to airway protection.

Muscle Spindle

Stretch receptor within skeletal muscle sensing length changes, important for jaw/tongue tone.

Golgi Tendon Organ

Tension receptor in muscle tendons monitoring force of contraction.

Laryngeal Elevation

Upward and forward movement of larynx aiding airway closure and UES opening.

Epiglottic Inversion

Motion of epiglottis folding to cover laryngeal inlet during swallow.

Periform Sinuses

Pharyngeal recesses that channel bolus around laryngeal opening.

Dentition

Arrangement and condition of teeth, vital for effective mastication.

Presbyphagia

Age-related, nonpathologic changes in swallow function.

Mechanoreceptor

General term for receptors responsive to physical deformation; includes tactile receptors.

Peristaltic Wave

Sequential contraction pattern propelling contents through a tubular structure.

Central Nervous System (CNS)

Brain and spinal cord structures coordinating sensory input and motor output for swallowing.