Dysphagia Flashcards
What occurs in the pre-oral phase
- SEE the bolus CN II (Optic)
- SMELL the bolus CN I (Olfactory)
- SALIVARY glands initiated
- Parotid CN IX (Glossopharyngeal)
- Submandibular CN VII (Facial)
- Sub lingual CN VII (Facial) - VOCAL ADDUCTION INITIATED
- interarytenoid CN X
- Lateral cricoarytenoid CN X
What occurs in the oral phase: Bolus acceptance
LIPS OPEN
- Orbicularis oris relaxes CN VII (facial)
- Risorious, zygomaticus, and levator labii superioris CN VII (facial) may contract.
JAW OPENS
*Jaw closers relax:
- Masseter CN V
- Temporalis CN V
- Medial pterygoid CN V (trigeminal)
*Jaw openers activate:
- Lateral pterygoid pull jaw forward CN V
- Anterior belly of digastric CN V
- Geniohyoid ansa cervicalis
- Mylohyoid CN V
TONGUE MAKES A CUP FOR BOLUS
-Intrinsic tongue muscles CN XII (hypoglossal)
JAW CLOSERS PULL MOUTH CLOSED
ORBICULARIS ORIS CONTRACTS TO PULL FOOD OFF SPOON/FORK
What occurs in glossopalatal approximation
BASE OF TONGUE APPROXIMATES WITH PALATE TO CONTAIN BOLUS ORALLY
- Palatoglossus CN IX, CN X (Pharyngeal Plexus)
- Styloglossus CN XII (Hyoglossus)
- Posterior belly of digastric CN VII (Facial)
- Stylohyoid CN VII (Facial)
ONCE BOLUS IS READY TO SWALLOW, MUSCLES CAUSE GLOSSOPALATAL APPROXIMATION MUST RELAX AND TONGUE BASE MUST DROP
- Hyoglossus CN XII
- Genioglossus CN XII
What occurs in oral phase: bolus manipulation
MASTICATION + BOLUS PREPARATION
-Midline of elevates to move bolus between teeth
- Intrinsic muscles of the tongue move bolus around oral cavity CN XII (hypoglossal)
- Oral sensory receptors inform tongue of position of bolus CN V (trigemial) CN VII (facial)
- Extrinsic muscles of the tongue position tongue with posterior tongue approximating the palate CN XII
- Jaw openers and closers work antagonistically
What happens in oral phase: Bolus awareness
TOUCH IS MODULATED
- Hard palate + teeth CN V (trigeminal) (maxillary)
- Cheeks, FoM, though from anterior 2/3 tongue CN V (mandibular)
- Soft palate + adjacent pharyngeal wall,
- Touch for posterior 1/3 of tongue + faucial pillars CN IX
TASTE IS PERCEIVED
- anterior 2/3 of tongue CN VII
- Posterior 1/3 tongue CN IX (glossopharyngeal)
What happens in oral phase: bolus transfer
ONCE BOLUS IS READY, TONGUE TIP FOLLOWED BY TONGUE BLADE PUSHES BOLUS INTO OROPHARYNX
- Superior longitudinal intrinsic tongue muscle CN XII
- Superior pharyngeal constrictor* (glossopharyngeus CN PP)
- Styloglossus CN XII *
*Move tongue posteriorly in oral cavity
What things occur in the pharyngeal phase of swallowing?
- Hyolaryngeal excursion
- Velopharyngeal closure
- BoT (base of tongue) and PPW (posterior pharyngeal wall) approximation
- Shortening of the pharynx
- Air way protection
- UES opening
What occurs in the pharyngeal phase: hyoid excursion?
Superior hyoid movement:
- Stylohyoid CN VII
- Posterior belly of digastic CN VII
- Middle Pharyngeal constrictor PP
- Thyrohyoid CN AC
Anterior hyoid movement:
- Anterior belly of digastiric CN V
- Mylohyoid CN V
- Geniohyoid CN AC
Why should a be wary of someone with cranial nerve damage to CN V and VII?
These are the main nerves involved in hyoid excursion and it is a very careful balance of muscles required.
What occurs in the pharyngeal phase: BoT approximating PPW, Pharyngeal shortening and bolus clearance
Retraction + Elevation of tongue base
- Stylohyoid (CN VII)
- Posterior belly digastric (CN VII)
- Styloglossus (CN XII) *
- Glossopharyngeus (PP) (SPC)
Pharyngeal Shortening
- All the above muscles
- Stylopharyngeus (CN IX)
- Salpingopharyngeus (PP)
- Palatopharyngeus (PP)
Bolus clearance
- Superior
- Middle
- Inferior pharyngeal constrictor (PP)
What occurs during the pharyngeal phase: UES opening?
Relaxation of
-Cricopharyngeus CN V
Anterior hyoid movement
- Anterior belly digastric CN V
- Mylohyoid CN V
- Geniohyoid CN V
Airway protection mechanisms
-Potential true and false vocal fold adduction
- Glossopalatal approximation
- True and false vocal fold adduction in expiration phase of breathing
- Ventricular fold adduction and anterior tilt to cover posterior 2/3 glottis
- Pharyngeal shortening to squash quadrangular membrane to cover anterior 1/3 of glottis
- Epiglottic deflection
What is the NTS?
- The Nucleus Tractus Solitarius
- The primary sensory nucleus for VII (facial), IX (glossopharyngeal), X (Vagus) and XI (spinal Accessory)
- All afferent information from the larynx and pharynx travels to the NTS via the above nerves
-It also receives secondary input from V (trigeminal)
What is the NA?
- Nucleus Ambiguus
- Primary motor nucleus of the IX (glossopharyngeal), X (Vagus) and XI (Spinal Accessory)
- Can recieve sensory input directly from the superior laryngeal nerve in order to have a reflexive cough
What types of input are required for onset of the pharyngeal response?
- Superficial Sensory Stimulation (information from I, II, V, VII, IX, V)
- Deep muscle spindle receptor stimulation: Movement of the base of the tongue dropping
- For ingestion, cortical input: recognition of bolus
- This information is sent to NTS where it must reach the electromechanical threshold to trigger the pharyngeal response
-Then sent to the NA for execution
