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
Which muscle is responsible for velopharyngeal closure?
Levator veli palatini CN PP
How does the epiglottis move?
It occurs when the hyoid moves anteriorly and pulls the base of the epiglottis anteriorly
What occurs with the quadrangular membrane?
Laryngeal shortening compresses the quadrangular membrane over the anterior aspect of the glottis
What does the swallowing central pattern generator comprise of?
- NTS
-NA - Reticular fibres and interneuons facilitate communication between neurons
Describe the pathway of sensory input
Sensory imput goes into cranial nerve nuclei, to primary cortex areas (primary somatosensory cortex), associtation areas (for recognition and procressing), to limbic system and frontal lobe (for emotive and executive function), to NTS, to NA
Tongue muscles and their movements + innervation
Styloglossus
- elevates and retracts tongue
- XII
Hyoglossus
-Pulls tongue down
- XII
Genioglossus
- Pulls tongue out and depresses centre
- XII
Palatoglossus
- Pulls back of tongue up
- PP
What is cricopharyngeus innervated by?
CN X
What occurs with the Arytenoids?
tilt over the posterior area of the glottis
Sensory imput of oropharynx, hypopharynx, larynx, carina
Oropharynx and Hypopharynx
- PP
Larynx
- Superior laryngeal nerve of vagus
Trachea/bifurcation
- Reccurent laryngeal nerve of vagus
