Cranial Nervous
Lesions to this nerve alone can cause aspiration
Why?
Internal Superior Laryngeal Nerve (SLN) of CNX (vagus)
Sensory to supraglottic larynx
(cricoarytenoid joints, posterior aspect of larynx, and pharyngeal mucosa in pyriform sinuses)
What are the two main goals of swallowing
Bolus efficiency (BE): moving the ingested bolus into the esophagus in a timely way without significant residue, effort, or repeat swallows (cohesive, rapid)
Airway protection (AP): preventing ingested materials from entering the larynx and/or trachea. When things get into lungs, theirs a greater chance of pneumonia
Efficient bolus movement is accomplished when coordinated neuromuscular contractions and relaxations create zones of ____ pressure on the bolus and zones of ______ pressure below the level of the bolus.
High
Negative (low)
Creating zones of high and low pressure is largely accomplished by the coordination and strength of the swallowing valves: lips, velum, airway closure, and the PES opening and closing
laryngeal elevation helps create a negative zone of pressure in the pharynx, particularly in the region of the PES. This allows the bolus to move rapidly, and therefore safely, from a zone of high pressure into a zone of negative pressure
What are the three main elevators of the jaw?
What is the primary depressor of the jaw?
Temporalis, Masseter, Medial Pterygoid
Lateral Pterygoid
What are the stages of swallowing, briefly describe what happens in each stage
Stages of Swallowing
1) Oral Prep Phase
Food is masticated in preparation for transfer
2) Oral Stage
Food is transferred from the mouth to the oropharynx
3) Pharyngeal stage
begins when the bolus arrives at the level of the valleculae and ends when the PES closes
4) Esophageal stage
All the muscles of the soft palate are innervated primarily by _____ except the _______, which is innervated by_______
CNX,
tensor veli palatini,
CNV
Name four motor processes that contribute to airway protection
1. Respiration ceasing
2. Laryngeal valve closing
3. laryngeal elevation
4. tongue base retraction
5. epiglottic tilt
6. Vallecular spaces dividing bolus
7. Thyroid Hyoid contraction
8. Opening of PES/UES
What could be a pathophysiology for a bolus to move from a zone of high pressure into another zone of high pressure. What risk does this create?
pathologic condition (e.g., muscle weakness or incoordination) due to aging, nerve damage, muscle damage
inhibits bolus flow and results in stasis and residue that may be aspirated into the airway.
What are the 4 primary hyoid bone elevators
1. Geniohyoid
2. Mylohyoid
3.Stylohyoid
4. Diagastric (anterior, posterior)
What triggers the swallow trigger?
a swallow is triggered by sensory stimulation to the oropharyngeal region - once triggered (motor response), a cascade of swallowing events occurs including:
Velar elevation
Laryngeal vestibule closure
Pharyngeal constriction and elevation
Upper esophageal opening
What innervation allows for appropriate mastication?
CNV – Trigeminal
The mandibular branch of the trigeminal nerve CNV - innervates the principal muscles for chewing behaviors.
CNVII – Facial
Facial - Innervates lower facial muscles attached to the maxillae and mandible of the skull.
CNXII – Hypoglossal
innervates the tongue, might be most important muscle for swallowing, scoop, scrape and transport posteriorly
Name two sensory aspects that contribute to airway protection
CNX SLN: sensory protective mechanism of supraglottic
CNXRLN: sensory protective mechanism of subglottic
1.Why are salivary glands important?
2.What are the three salivary glands?
3.What can cause xerostomia?
1.Antibacterial and antacid properties, which prevents tooth decay and infections, Moistens dry food, Keeps oral mucosa moist which reduces friction of the bolus
2. Parotid (CNIX), Submandibular (CNVII,70% of salivia), Sublingual (CNVII).
3.Caused by medications, radiation, neural damage, and aging
_____ is biggest player for swallowing with UES but is not the only thing that makes up the UES
cricopharyngeus (CP)
Inferior pharyngeal constrictor, Right above PES
Thyropharyngeus (main part)
Cricopharyngeus or CP (lower part, no raphe)
1. What parts of a swallow are volitional
2. What parts are reflexive
1. Oral preparation (cortical control), Posterior lingual propulsion
2. Velar elevation, Laryngeal vestibule closure, Pharyngeal constriction and elevation, UES opening, esophageal stage
The cranial nerves involved in swallowing send sensory information to the _____. Motor components are organized in the ____. Together they compose the “swallowing center” located in the _____ of the brainstem.
NTS
NA
Medulla
What is the purpose of velar elevation?
Bolus Efficiency
The velum elevates in the posterior direction, making contact with the posterior pharyngeal wall
needs to be rapid and complete to prevent nasal regurgitation
Help propel bolus- build downward pressure on the bolus
Our the tensor veli palitini is the main muscle responsible for elevating the velum (trigeminal nerve)
The symptom of impaired bolus transport might be caused by what impairment?
Lingual weakness, reduced sensation, motor planning/discoordination, tongue base weakness (CN XII)
Name the following muscles
1. Cheek muscle
2. lip protruding, rounding, inverting
3. Smiling muscle
1. Buccinators
2. Orbiculus oris
3. Zygomaticus major
What 3 mechanisms play a role in the opening of the UES/PES
1. Mechanical traction (1, 2, and 3)
- Posterior tongue retraction
- Hyoid Bone/laryngeal valve elevation
- Thyroid and Cricoid elevation
2. Brainstem disinhibition, parasympathetic signals carried by CN IX and CNX to the brainstem relax PES
3. Bolus driving forces (Responsive to pressure and bolus volume, Longer opening for bigger bolus)
1. Define the pharyngeal plexus.
2. It is motor to all muscles of the ____besides _____ which is directly innervated by _____
Bundle of nerves innervating most of the palate, pharynx, larynx. Contains portions of IX, X(pharyngeal branch), XI
Larynx, Stylopharyngeus, IX
What are some medical consequences of dysphagia
Aspiration pneumonia
Dehydration
Dehydration can lead to increased mental confusion and generalized organ system failure, both of which lead to greater decompensation of swallowing
Undernutrition
which adversely affects energy levels (ability to sustain a swallow), and if severe or chronic, compromises the immune system.
Psychosocial Consequences
may limit the extent to which a person might socialize, leading to major changes in a normal lifestyle
Fear of overt choking episodes and the associated discomfort might contribute to social isolation and accompanying depression.
The symptom of Pen/asp during swallow could be caused by what impairment
Reduced laryngeal closure
1. What are the extrinsic muscles of the tongue?
2. What are the intrinsic muscles of the tongue?
What purpose do they serve in swallowing?
1.Styloglossus (CNXII), hyoglossus (CNXII), genioglossus (CNXII), palatoglossus (CNIX, CNX, CNXI)
2. Transverese, longitudinal, vertical (all CNXII)
3. Bolus shaping and transportation
The pharyngeal constrictors together are termed the _______
What is Natalies favorite color?
_________
Orange