Dysphagia

CN ___ provides sensory information about the anterior faucial pillars

IX

What causes GERD?

1. Delayed gastric emptying. The food remains in the stomach for too long. 2. Low LES tone.

What happens in the pharyngeal stage?

1. Downward movement of the tongue (propels bolus downward) 2. Pharynx elevates, shortens, and constricts (squeezing bolus through) 3. Larynx elevates/closes (airway protection) 4. Esophagus opens/closes (keeps it from returning to pharynx)

What happens in the esophageal stage?

1. Larynx lowers 2. CP segment closes 3. Breathing resumes 4. Bolus travels to stomach

What happens in the oral stage?

1. Tongue quickly, forcefully and efficiently propels the prepared bolus into the pharynx and triggers the swallowing response. 2. The soft palate closes off the nasal passage.

What does the swallowing center do?

The swallow center generates predetermined "patterns" of motor output so that the swallowing is executed efficiently and smoothly.

Which muscle is a "switch hitter" meaning it both lowers OR raises the larynx?

Thyrohyoid.

Why do we say "we don't simply treat the aspiration?"

To begin with, SLPs address all stages of swallowing. Intervention to dysphagia includes all feeding techniques and strategies that increases the efficiency of posterior transit, stimulates swallowing response, improves pharyngeal transit of material, protects the airway and clears the esophagus. Secondly, "eating" is very complex and swallowing issues can affect numerous aspects of life - not only the physical well-being, but psychological well-being, daily activities and participation, and family finance as well. The intervention outcomes should maximize functional improvements that are important to the individual, and optimize the individual's potential to participate in meaningful activities.

What is the primary driving force of the bolus into the pharyx?

Tongue/lingual propulsion.

What types of sensory input trigger the swallow?

Touch(tactile); taste(especially sour); temperature(cold); sensory properties of the bolus.

Dr. _________________developed a protocol for examining swallowing using a modified version of a barium swallow test called the "cookie swallow".

Jeri Logemann

Know these places: 1=vocal folds, 2=vestibular fold, 3=epiglottis, 4=aryepiglottic fold, 5=arytenoid cartilage, 6=piriform sinuses, 7=dorsum of the tongue(epiglottic vallecula)

Lable pictures

How long should it take a very thick bolus to move back during the oral stage (this is called "oral transit time"?

Less than 0.5 second but always less than 1.0 sec regardless of consistency.

How long is typical pharyngeal transit time (i.e. duration of bolus transit through the pharynx)?

Less than 1 second.

How do the longitudinal (vertical) muscles of the pharynx play a role in laryngeal elevation?

Longitudinal pharyngeal muscles connect to higher structures (i.e. palate, styloid process) and to the hyo-laryngeal complex and therefore when they contracts they help elevate both the pharynx and the larynx.

Collectively what do the infrahyoid muscles do?

Lower the larynx.

What is the NTS and what is its role in regulating swallowing?

The nucleus tractus solitarius (NTS) is a pair of neuro cell bodies located in the medulla oblongata. Nucleus Tractus Solitarius(NTS) is formed by the fibers of the IX, X and VII. The NTS receives and integrates sensory input from CN, V, VII, IX, X and then activates the motor outputs of swallowing through interneurons.

Why is the oral preparation stage the most important stage from a QOL perspective?

The oral preparation stage gives us the pleasure of eating and this is the reason why we eat.

What is the primary purpose of the oral preparation stage?

The purpose is to break food down, mix it with saliva for preparation to swallow.

What is the primary driving force of the bolus during the swallow?

The tongue.

What muscles are active during mastication?

There are four muscles involved in mastication - the temporalis, the masseter, the medial pterygoid and the lateral pterygoid.

What makes up the swallowing center?

There are many parts that make up the swallowing center: cerebral cortex, brain stem, deep brain structures, descending/ascending pathways, interneurons, cerebellum.

What is the role of the arytenoid cartilages in laryngeal vestibular closure?

They slide forward to shorten the vocal folds, reducing the opening to the larynx, and closes the vocal folds.

Why is the pharyngeal stage the most important physiologically?

This is the stage when the bolus is pushed downwards, the airway is closed, and the esophagus is open. Therefore issues in the pharyngeal stage would have the most impact on the efficiency and safety of swallowing response.

In the neurology of swallowing online lecture I simplified the CN that innervate the UES (this is CN X) but you now know that CN IX/X (as part of pharyngeal plexus) with ansa cervicalis innervate the UES to inhibit movement allow the UES to contract.

True

How does the bolus travel through the esophagus?

Upon entering the esophagus, wave-like esophageal muscle contractions called peristalsis carries the bolus toward the stomach.

An elderly person with _______________________ is at a high risk for dysphagia.

dementia

What is dysphagia?

difficulty in swallowing

The term ___ is used interchangeable with GERD.

esophagitis

Touch, pain, temperature are sent to the brainstem/cortex via _______ sensory receptors (general/special)

general

What muscle that elevates the larynx is innervated by the cervical plexus?

geniohyoid (cervical plexus) thyrohyoid (cervical plexus)

The most common sign of an esophageal web is difficulty swallowing solid foods especially ___ and ______ that stick.

meats; bread

Dehydration may be a side effect of __________________.

medication

The base of tongue and hyoid bone move in_____ directions.

opposite

The wavelike progression of a bolus through the esophagus is called _______.

peristalsis

Swallowing disorders affect the patient's QOL from physical, medical, financial and _________________ dimensions. They may also be life threatening.

psychological

The esophagus sites behind the ___ and isn't a straight shot down like we see in anatomical drawings.

trachea

What is Nissen fundoplication?

treatment of GERD: part of the stomach is wrapped around the esophagus like a collar to provide a one-way valve effect

We may suspect dysphagia if the patient has _____________ weight loss.

unplanned

What is the UES?

upper esophageal sphincter / pharyngoesophageal sphincter / cricopharyngeal segment

Another name for a Modified Barium Swallow Study (MBSS) is:

videofluoroscopic swallow study [VFSS]

When a bolus enters the vestibule, it doesn't necessarily enter the trachea. Why not?

Because The TVF, which sits at the bottom of the laryngeal vestibule, closes first. The larynx closure occurs from bottom to top and it can squeeze out penetrated bolus.

Why is BOT retraction important for airway protection?

Because the base of tongue (BOT) retraction helps move the epiglottis into a horizontal position, inverting over the larynx to prevent aspiration.

What is the last thing to close?

Laryngeal vestibule.

Contact of the _______ with the ____ retain the bolus in the oral cavity and preventing the bolus from spilling into the ________

back of the tongue; soft palate; pharynx

Murray refers to the movement of the bolus during mastication as

bolus formation

A _________________ stroke is the most likely area of the brain to cause the most severe dysphagia.

brainstem

How does the larynx close during the swallow?

1. BOT moves posteriorly 2. Elevation/anterior displacement of larynx 3. TVF close as arytenoids tilt up, move forward to the base of the epiglottis and together 4. FVF close and AE folds move medially 5. Epiglottis closes laryngeal vestibule

List events (what happens) during the oral preparation stage.

1. Lip closure 2. Bolus mastication 3. Bolus formation 4. Bolus hold - front and center by tongue against hard palate 5. Saliva activates sensory receptors for taste, temperature, and pressure

How does the CP segment open?

1. The UES relaxes 2. UES is pulled open by the superior/anterior elevation of the larynx (& shortening of the posterior pharyngeal wall) (3. BOT drives the bolus back and pharyngeal contraction squeezes the bolus (driving force of muscle pressure). 4. Air pressure changes draw the bolus into the esophagus)

It takes about ___ seconds for liquids to travel through the esophagus and enter the stomach.

3

When the base of the tongue retracts, it pushes the epiglottis into a ________ position.

horizontal

Elevation and anterior displacement of the larynx is also referred to as _____.

hyo-laryngeal elevation

Vision, balance, smell, taste are all considered ________ sensory (special/general)

special

The epiglottis attaches to the thyroid cartilage through the ______ ligament.

thyroepiglottic

Since the epiglottis is part of the larynx, laryngeal elevation moves the epiglottis _up_ via its attachment to the ___ cartilage.

thyroid

Epiglottic inversion occurs due to contributions from the ____, ____, ____ and pharynx.

tongue, larynx, hyoid bone

Name one congenital cause of dysphagia affecting the oral preparation and oral stages.

Cleft Palate

Is it normal for you to occasionally have reflux?

Yes

What are the 5 parts of laryngeal closure?

BOT moves posteriorly Elevation/anterior displacement of larynx TVF close as arytenoids tilt up, move forward to the base of the epiglottis and together FVF close and AE folds move medially Epiglottis closes laryngeal vestibule

What is Barrett's esophagus?

Barrett's esophagus is a condition in which the esophagus becomes damaged by acid reflux, which causes the lining to thicken and become red resembling the lining of the stomach and intestines.

Why is the base of tongue retraction important?

(1)Base of the tongue is the primary force for bolus propulsion. (2) help to move the epiglottis into a horizontal position, inverting over the larynx. Weakness of tongue base retraction can render inadequate the force of pharyngeal propulsion, resulting in retention of all or part of the bolus in the valleculae and pyriform sinuses after swallowing.

What kind of pressure is needed to move the bolus through the pharynx? (We talked about 3).

(1)The BOT retracts, and the high pressure pushes the bolus down. (2) Then the pharyngeal muscles contract, the high pressure in this spot pushes the bolus down. (3) the esophagus opens, the negative pressure in the esophagus sucks the bolus down.

What is the primary driving force of the bolus into the pharynx?

Base of Tongue retraction.

Describe the general components of the oral preparation stages of swallowing and things to remember that are specific to oral preparation stage.

1 velum is down 2 airway is open 3 larynx is at rest 4 timing movement depends on consistency 5 voluntary 6 the reason why we eat

How does the epiglottis close?

1. BOT moves back(pushes the epiglottis down, but not all the way) 2. Larynx moves up and forward(helps fold the epiglottis over) 3. Aryepiglottic muscles contracts(pull the epiglottis down) 4.Pharyngeal contraction helps push the epiglottis over

What are the 4 parts of epiglottic closure?

1. BOT moves back(pushes the epiglottis down, but not all the way) 2. Larynx moves up and forward(helps fold the epiglottis over) 3. Aryepiglottic muscles contracts(pull the epiglottis down) 4. Pharyngeal contraction helps push the epiglottis over

What is a gastroenterologist?

A gastroenterologist is a medical expert in digestive health and issues related to the stomach, intestines, and bowels.

What does "traction force of hyoid on larynx" mean?

Because the larynx is attached to the hyoid bone. The hyoid is anchored so when the muscles run between the hyoid bone and larynx contract, they pull the larynx up to the hyoid bone.

Why might you still see some soft palate movement if CN IX and CN X are damaged?

Because the tensor veli palatini is innervated by CN V.

What is the role of the ELM vs ILM for swallowing?

ELM: elevate or lower the larynx. ILM: close the vocal folds during swallowing.

Collectively what do the suprahyoid muscles do?

Elevate the hyoid bone.

In ____ the food comes from the esophagus back into the pharynx, whereas in _GERD__ the material comes from the stomach.

Achalasia

____occurs when nerves in the esophagus become damaged. As a result, the esophagus becomes paralyzed and dilated over time and eventually loses the ability to squeeze the bolus into the stomach.

Achalasia

This esophageal disorder can be very painful and cause dysphagia and regurgitation. If it's severe, the patient may need an esophagectomy. What is it?

An esophagectomy is a surgery where the patient has to take the esophagus out.

_______is a chronic disorder in which large numbers of a particular type of white blood cell called eosinophils are present in the esophagus.

Eosinophilic Esophagitis

What is another name for the cervical plexus?

Ansa cervicalis

Why is laryngeal elevation important for epiglottic closure?

As larynx elevates, the epiglottis moves closer to the tongue.

Why is it important that the pharynx shortens and elevates during the swallow?

As the pharynx elevates, it shortens the distance between the upper and lower pharynx, which is the distance for the bolus to travel down to the esophagus, therefore enhancing more efficient transportation of the bolus.

If a nut gets stuck on the base of your tongue, you would feel it there because of this cranial nerve.

CN IX

What cranial nerves innervate the palatoglossus?

CN IX and X

If you bite your tongue tip, what cranial "feels" that?

CN V

Which cranial nerve is responsible for detecting (feeling) the location of the bolus in the oral cavity?

CN V

You FEEL the cold ice cream on your tongue thanks to this cranial nerve.

CN V

What cranial nerve is important to feel the position of the tongue when swallowing and speaking?

CN V and CN IX

What are the cranial nerves responsible for sensory input to the brainstem for swallowing to trigger?

CN V, VII, IX, X(internal branch of SLN)

What are the cranial nerves responsible for motor output to the brainstem for swallowing to trigger?

CN V, VII, IX, X, XI, XII, C1-3

What cranial nerve innervates the muscles of mastication?

CN V3, lingual nerve, the mandibular branch of the trigeminal nerve, innervates the muscles that move the mandible; CN VII innervates facial muscles; CN XII innervates all tongue muscles except palatoglossus, which is innervated by CN IX and X.

You taste ice cream on the anterior 2/3 of your tongue thanks to this cranial nerve.

CN VII

What cranial nerve innervates the muscles of the face?

CN VII.

What CN innervates all of the muscles that close the vocal folds during the swallow?

CN X

What cranial nerve innervates the muscles of the tongue (with the exception of the palatoglossus)?

CN XII hypoglossal.

What parts of the CNS are involved in swallowing?

Cerebral cortex Brain stem Deep brain structures Descending/ascending pathways Interneurons Cerebellum

What foods should people with GERD avoid?

Chocolate, fatty foods, onions, peppermint, garlic, (nicotine).

What is the difference between aspiration and choking?

Choking occurs when the airway is obstructed by food, drink, or foreign objects. Aspiration occurs when food, drink, or foreign objects are breathed into the lungs. Aspiration can be silent.

What is the name of the tract that carries information from the cortex to the cranial nerves in the brainstem?

Corticobulbar tracts

What muscle makes up the lowermost part of the inferior constrictor muscle?

Cricopharyngeus muscle

What muscle makes up the upper most part of the UES?

Cricopharyngeus muscle

In addition to aspiration and aspiration pneumonia, what are 3 other consequences of swallowing disorders?

Dehydration, malnutrition, weight loss.

What happens during a normal swallowing event?

During mastication in the oral cavity, the food is crushed and mixed with saliva to form a bolus. As the food bolus reaches the pharynx, the swallowing reflex is initiated by the swallowing center in the central nervous system, causing the food to be further pushed back into the pharynx and the esophagus. In the pharyngeal phase the larynx is closed involuntarily by the epiglottis and vocal cords, and breath is inhibited temporarily. The closure of the larynx by the epiglottis protects the lungs from injury. The bolus then moves further downwards into the esophagus. Rhythmic movement of the esophagus carries the bolus to the stomach. The lower esophageal sphincter closes to prevent gastroesophageal reflux. Swallowing output is preprogrammed, and once triggered, the muscles contractions/relaxations will take place smoothly.

How does the CP segment "know" how wide to open to receive a bolus?

During mastication, CN V provides sensory feedback from the hard palate and anterior ⅔ of the tongue. It sends back the information to the central nervous system, and then the CNS sends information to the CP segment. Based on the feedback of CN V about the size of the incoming bolus, the CP segment anticipates how wide to open.

What anatomical structures are all integrated during mastication?

During mastication, the lips are essential for retaining the food in the oral cavity and for directing the food back to the tongue and teeth for bolus mastication and transfer. The movements of the tongue, mandible, dentition, soft palate, and muscles of the buccal cavity are temporally integrated to grind and position the food.

How is pressure key in a normal swallow?

During swallowing, muscle contractions and relaxations create zones of high pressure on the bolus and zones of negative pressure below the bolus. The high pressure drives the bolus away. The negative pressure sucks the bolus down. The movement of the bolus is a pressure driven event created by sealing off "spaces" and aided by muscle contractions.

How does dysphagia impact QOL?

Dysphagia affects the quality of life in a number of ways: A. Functional Limitations: 1. Limitations on the types of food that a patient can swallow safely 2. Patients may be limited to a specific diet of foods that they do not like 3. Time required to swallow and finish a meal may be longer 4. Oral structures may limit the types of food to swallow 5. Some foods may cause the patient to choke B. Activities and Participation: 1. Patients on a non-oral diet may be reluctant to attend events where food is served. 2. Foods related to cultural or religion may not be available to patient 3. Ability to hold and use straw or utensils may limit eating/drinking 4. Ability to eat in a group setting may limit activities 5. Ability to prepare meals may reduce food intake C. Environmental Factors:1. Changes in room lighting or sound may limit eating2. Proper eating arrangements may be limited due to room spaces 3. Eating in public may present unwanted attention4. Use of personal care providers may be needed during mealtimes

What does dysphagia therapy address?

Dysphagia therapy addresses all stages of swallowing, which includes all feeding techniques and intervention strategies that increases the efficiency of posterior transit, stimulates swallowing response, improves pharyngeal transit of material, protects the airway and clears the esophagus.

What pulls the tongue down?

Genioglossus.

Explain the anatomy and CNs that are responsible for sensation in oral preparation stage.

Hard and soft palate, anterior ⅔ tongue general sensation (touch, temperature, pain) - CN V Tongue - anterior 2/3 taste - CN VII; posterior 1/3 taste and touch - CN IX

Why is pharyngeal constriction important to epiglottic inversion?

Help to push the epiglottis down.

What muscle runs from the hyoid bone to the tongue?

Hyoglossus.

What are the primary goals of swallowing therapy?

Improve efficiency - Moving the prepared bolus into the esophagus in a timely way without significant residue, effort, or repeat swallows. Airway Protection - Preventing food/liquids from entering the larynx and/or trachea.

What is an interneuron?

Interneurons connect with other types of neurons such as the motor and sensory neurons. They provide proper connections so that sensory impulses can be changed into motor impulses.

The muscles of the tongue can be divided into two main groups. What are these?

Intrinsic lingual muscles and extrinsic lingual muscles.

How do the arytenoids move during laryngeal closure?

It first tilts up, then moves forward and together.

What is the role of pharyngeal contraction in bolus transit through the pharynx?

It is the clearing force to drive the bolus through the pharynx.

What is the purpose of pharyngeal contraction (squeezing) and how is this accomplished?

It is the clearing force to drive the bolus through the pharynx. It is accomplished by muscle contractions. When the pharyngeal constrictor muscles contract, they tense and narrow the pharynx, squeezing out the bolus. And when the longitudinal pharyngeal muscles contract, they elevate both the larynx and the pharynx, encouraging the inversion of the epiglottis.

Explain the anatomy and CNs that are responsible for movement in oral preparation stage.

Muscles that move the mandible - temporalis, masseter, lateral/medial pterygoid - CN V3---lingual nerve, mandibular branch of trigeminal Muscles that move the face - Obicularis Oris, buccinator - CN VII Muscles that move the tongue - intrinsic and extrinsic lingual muscles - all by CN XII except palatoglossus (CN XI &X)

Does velar elevation protect the airway?

No

Is the swallowing center located in one part of the brain?

No.

Does the UES "contract" to open?

No. The UES opens via relaxation.

What muscles of the face are important for mastication?

Obicularis Oris Buccinator

What is closed and open in each stage of swallowing?

Oral prep: Open: VP port, vocal folds, pharynx; closed: lip, tongue in contact with the soft palate, esophagus. Oral: Open:Pharynx, vocal folds; Closed: Lips, VP port, esophagus Pharyngeal: open: esophagus Closed: Lips, VP port, vocal folds, FVF, Laryngeal vestibule, BOT in contact with PPW. Esophageal: open: VP port, vocal folds, FVF, Laryngeal vestibule, pharynx Closed: esophagus

What is the risk of aspiration in each stage of swallowing?

Oral prep: back of the tongue is not elevated(bolus escape to the pharynx before swallow) Oral: if the VP port is not sealed, not enough pressure change to drive the bolus down quickly and stretch the esophagus open, thus leaving retention in the pharynx Pharyngeal: BOT retraction(the bolus travels slow), hyo-laryngeal elevation(esophagus not open wide & larynx not fully closed), epiglottic inversion(larynx not closed), pharyngeal elevation/contraction(sophagus not open wide), TVF/FVF/AE folds not closed properly Esophageal: UES not closed(bolus travels back).

What happens in the oral preparation stage?

Oral preparation stage: Lip closure Bolus mastication Bolus formation Bolus hold - front and center by tongue against hard palate Saliva activates sensory receptors for taste, temperature, and pressure

Which stage of swallowing is the real reason why we eat?

Oral preparation.

What are the 4 phases of swallowing?

Oral preparatory phase, oral phase, pharyngeal phase and esophageal phase.

What is phagophobia?

Phagophobia is a fear of swallowing. It is expressed in various swallowing complaints without any apparent physical reason detectable by physical inspection and laboratory analyses.

What inflammatory conditions/diseases can affect the pharyngeal stage of swallowing?

Pharyngitis, retro-pharyngeal abscess脓肿, acute epiglottitis.

Why is soft palate closure during the oral stage important?

Prevent nasal regurgitation Help to build pressure to encourage downward movement of the bolus.

Why is closure of the oral cavity at the tongue (or lips) and soft palate important?

Prevent regurgitation Help to build pressure to encourage downward movement of the bolus.

What is the purpose of saliva during oral preparation of the bolus?

Saliva activates sensory receptors for taste, temperature, and pressure .

A _____ is a specific type of "esophageal ring" causing narrowing of the lower esophagus.

Schatzki's Ring

How long is esophageal transit for solids? Liquids?

Solids:9 sec. Liquids: 3 sec.

What muscles pull the tongue back (retract the tongue?)

Styloglossus and hyoglossus.

The ___ is a branch of vagus that is important for triggering the swallow.

Superior Laryngeal Nerve

What happens at the very end of the oral stage?

Swallowing response is triggered.

During the oral preparation stage, the pattern of swallowing starts out volitionally but once it's initiated, chewing becomes more reflexive (T/F)

T

Esophageal stage problems may present as a "pharyngeal" problems (T/F)

T

Health professionals may use both "webs" and "rings" to refer to the same structure.

T

Technically GERD causes esophagitis.(T/F)

T

The CP segment must receive innervation to open, it can't just be stretched open. (T/F)

T

The anterior faucial pillars are the primary site where the response is triggered, but not the only site. (T/F)

T

The esophagus is collapsed at rest (T/F)

T

The terms "stricture" and "stenosis" mean narrowing and are often used interchangeable (T/F)

T

Without laryngeal elevation, you will not get full laryngeal closure (T/F)

T

During laryngeal closure, what is the FIRST thing to close?

TVF

The very last line of defense are the ___because once the bolus passes here, aspiration has occurred.

TVF

What muscle of the soft palate is innervated by CN V?

Tensor veli palatini.

What causes Cricopharyngeal Bar? What movement problems would you look for?

The CP bar may be caused by problems in the neuro system or the motor movements of the larynx or the pharynx or the pressure change. 1. The UES does not relax due to neuro problems. If it is a movement problem, we would look for the followings to see: 2. If the UES is not pulled open because the larynx is not moving superiorly or anteriorly. 3. If BOT does not drive the bolus back hard enough or pharyngeal contraction does not squeeze the bolus hard enough. 4. Air pressure changes that draw the bolus into the esophagus are not enough.

What is the position of the base of the tongue during mastication?

The base of tongue is elevated and in contact with the soft palate.

What does a bird's beak sign of the esophagus mean?

The bird's beak sign of the esophagus is used to refer to the tapering细长的 of the inferior esophagus in achalasia.

What happens if the CP segment doesn't open wide enough?

The bolus will be stuck on the top of the esophagus, which increases the chance of aspiration.

What is the cervical plexus?

The cervical plexus is a plexus of the anterior rami of the first four cervical spinal nerves which arise from C1 to C4 cervical segments in the neck.

What part of the brain controls all of the movements for the stages of swallowing?

The cortex.

How does the larynx elevate during the swallow?

The larynx is attached to the hyoid bone. The hyoid is anchored so when the muscles run between the hyoid bone and larynx contract, they pull the larynx up to the hyoid bone.

List factors that would impede UES opening:

The larynx is not elevation enough; The CP muscle spasms Something goes wrong in the esophagus The tongue strength is weak and the hyoid is not fixed.

How does the tongue move to propel the bolus backwards?

Upward and backward.

CN ___ provides sensory information about the anterior portion of the tongue and the hard palate.

V

What CN is responsible for sensing aspiration above the TVF? Below?

Vestibule to VF (CN X SLN-superior laryngeal nerve) Below TVF (CN X recurrent)

The swallow trigger marks the division between volitional and automatic events. What does this mean?

When a swallow is triggered by sensory stimulation, a cascade of swallowing events is automatically triggered. That is to say, the series of events are not innervated consciously.

What important sensory information is needed to adequately prepare the bolus for a swallow?

When preparing the bolus for a swallow, factors such as taste, temperature, and the viscosity and size of bolus are sensed. The trigeminal nerve (cranial nerve V), through its second and third divisions, provides sensory and motor innervations, respectively, to the muscles of mastication. Sensory information related to taste is mediated by CN VII (anterior two-thirds of the tongue) and CN IX (posterior one-third of the tongue).

When/where is the trigger expected for healthy young vs older adults?

When: young: at the same time when the oral stage ends. The swallow response time should be 0 in healthy young adults. Old: The initiation of the swallow is delayed. Study suggests there is a .06s delay after the bolus was at the ramus of the mandible. Where: Young: Anterial Faucial Arch is the primary spot to trigger a swallow response. Old: The trigger point moves downward and backward, it might be at the posterior pharyngeal wall, the superior surface of the epiglottis, or even the pyriform sinuses.

Web/rings can cause you to cough because it triggers CN __ even though you haven't aspirated.

X

What we do to eat and drink requires input from both higher and lower levels of the CNS (T/F)

Yes.

Is it normal for an older person to trigger the swallow later (e.g. at a lower place in the oropharynx) than a younger person?

Yes. As a person ages, the trigger point becomes lower in the pharynx.

Are both hemispheres involved in swallowing?

Yes. But most people have left hemispheric dominance.

A ____results from posterior herniation of esophageal mucosa into an area just ___ the cricopharyngeus (CP) muscle and __ the inferior pharyngeal constrictor muscle.

Zenker's Diverticulum; above; below