Deglutination + Phonation

Question 1

The larynx functions as a a _______ sphincter to control air coming in and out (via inspiration/ coughing)

Answer 1

Compound sphincter.

Question 2

Define the palatine tonsils. What is the clinical correlation associated with them?

Answer 2

These are lymphoid tissues that help mount an immune response for an infection that may be present at the oropharynx. Tonsillitis is the inflammation of the tonsils, involving painful swallowing.

Question 3

The parotid glands secrete saliva enriched with _________ enzyme and are innervated by parasympathetics that hitchhike on the ___________ nerve (from otic ganglion). On the other hand, the submandibular/sublingual ganglions secrete _______ and are innervated by ________ nerve.

Answer 3

Alpha-amylase, CN IX, Auriculotemporal nerve (CN V-3);

Mucous, Chorda tympani nerve (CN VII)

Question 4

Define Frey’s Syndrome.

Answer 4

This involves sweating and flushing over the skin near the ear and superficial to the parotid gland due to a crisis-crossing of autonomic along the auricular temporal nerve.

Question 5

Describe the nerves that innervate the tongue, relaying sensory information and supplying motor efferents.

Answer 5

CN VII = (Chorda tympani) taste sensation of anterior 2/3 of tongue
CN IX = taste sensation of posterior 1/3 of tongue
CN V-3 = general (somatic) sensation of anterior 2/3 of tongue
CN XII = skeletal motor efferents to the intrinsic muscles of tongue

Question 6

Define the Valleuculae of the epiglottis.

Answer 6

This is a landmark for the larynx and trachea. Food collecting here tilts the epiglottis forward, so the bolus can bypass the larynx and get into the esophagus through the piriform recess.

Question 7

What are the muscles of the tongue, their actions and innervations?

Answer 7

Genioglossus = protrudes and flattens the tongue;
Hyoglossus = retracts and flattens the tongue;
Styloglossus = elevates and retracts the tongue;
Palatoglossus = raises the back part of the tongue;
Intrinsic muscles = molds the food into a bolus, size depends on viscosity.
Tongue muscles innervated by CN XII, except palatoglossus (X)

Question 8

If the right CN XII is injured and a doctor asks a patient to protrude the tongue, what would occur?

Answer 8

The patient would still protrude the tongue but it comes out and deviates TOWARDS the affected right side.

Question 9

Where are the Hypoglossal nerve and lingual artery in reference to the hyoglossus muscle?

Answer 9

The Hypoglossal nerve is LATERAL to the hyoglossus muscle, whereas the tortuous Lingual artery (which is a branch of the external carotid artery) is located MEDIAL to that muscle.

Question 10

What are the muscles of the pharynx, their action and innervation(s)?

Answer 10

The pharyngeal muscles are all innervated by CN X except the Stylopharyngeus (IX, glossopharyngeal superficial). The 3 outer circular muscles function to constrict BEHIND the bolus. The 3 inner longitudinal muscles work to elevate the pharynx and contract BEFORE the bolus on its way to the esophagus.

Question 11

Where does the Salpingophayngeus attach to? What of the Palatopharyngeus?

Answer 11

Salpingopharyngeus - attaches to Eustachian tube and pharyngeal wall (X);
Palatopharyngeus - innervates the soft palate above the tongue (CN IX)

Question 12

What is the function of the nasopharynx? What 2 muscles can be found within it?

Answer 12

Conditions the air by increasing turbulence around the concha and moistening it before it reaches the lungs. The tensor palati (CN V3) stretches the palate and pulls it to the side and the levator palati (CN X) raises the soft palate.

Question 13

What cranial nerve would a Tonsillectomy risk lesioning?

Answer 13

This procedure may injure CN IX that results in a deficit to taste of the posterior 1/3 of the tongue and a whisper for subsequent months post-op.

Question 14

Describe the Piriform recess.

Answer 14

This region channels food between the inferior constrictors and the larynx in order to bring the bolus around the epiglottis and into the esophagus.

Question 15

What are the cranial nerves associated with regions involved in deglutination?

Answer 15

CN V2 = raises soft palate;
CN VII = tastes/senses food on anterior 2/3 of tongue;
CN IX = taste on posterior 1/3 of tongue + elevates pharynx;
CN X = outer circular muscles to constrict behind bolus;
CN XII = muscles of tongue (including intrinsics)

Question 16

How does the upper aerodigestive tract differ in infants, as compared to adults?

Answer 16

In the infant, the uvula and epiglottis contact each other, thus allowing him or her to take in food and breathe simultaneously. This differs in the adult where food must pass on either side of the piriform recess to enter into the esophagus.

Question 17

Describe an overview of the 5 steps to deglutination.

Answer 17

1. Tip of tongue touches palate; bolus pushed posteriorly; soft palate moves upward.
2. Bolus pushed into oropharynx, while nasopharynx closes; stylopharyngeus +superior constrictor contract to raisepharynx over bolus.
3. Bolus reaches vallecula > epiglottis tips inferiorly > “Stripping wave” on posterior pharyngeal wall moves inferiorly.
4. Palatopharyngeus pulls soft palate to root of tongue > stripping wave moves down > superior constrictors close oropharyngeal cavity > cricopharyngeus relaxes as bolus enters esophagus.
5. Stripping wave has last of bolus pushed out > epiglottis and nasopharynx are reestablished.

Question 18

What exocrine glands produce saliva and what specific nerves are they innervated by?

Answer 18

Parotid gland is innervated by CN IX, the lesser petrosal nerve. The submandibular/ sublingual glands are innervated by the CN VII, via the greater petrosal nerve.

Question 19

The tongue tastes the food on the anterior 2/3 through the _______ ________ (CN VII) and the posterior 1/3 through the CN ____.

Answer 19

Chorda tympani nerve (CN VII)

CN IX

Question 20

The tongue relays its general (somatic) sensation of food on the anterior 2/3 through the __________ _________ nerve. The posterior 1/3 sense of food on the tongue is relayed through the CN ____.

Answer 20

Lingual nerve (CN V-3);
CN IX

Question 21

The palate senses and tastes food through the _______ _____ nerve and CN ______.

Answer 21

CN V2 nerve for general sensation on palate and CN VII

Question 22

The ___________ muscle is closed when we breathe so we don’t get much air heading down the GI tract. The _________ is closed when we eat so we don’t inhale our food.

Answer 22

Cricopharyngeus muscle is closed when we breathe.

Epiglottis is closed when we eat.

Question 23

What muscles help to seal the nasopharynx during the involuntary phase of swallowing? What are their innervations?

Answer 23

Levator palati (CN X) and Tensor Palati (CN V3) work to seal the nasopharynx during deglutination.

Question 24

What muscles work to elevate the laryngopharynx during the involuntary phase of swallowing? What are their innervations?

Answer 24

Suprahyoids (CN V3 + VII), Mylohyoid (CN V3) and the pharyngeal constrictors (CN IX and X) elevate the laryngopharynx.

Question 25

What is the purpose of arytenoid cartilages?

Answer 25

These cartilages move to change the shape of the larynx, enabling us to produce different sounds. The anterior projections are the vocal processes while the lateral muscular processes are where internal laryngeal muscles attach.

Question 26

What is the false vocal chord made of?

Answer 26

The inferior free margin of the quadrangular membrane, which is the vestibular ligament, is the false vocal fold.

Question 27

A surgeon cautiously performs an operation on the thyroid gland of a singer. If the _______ _______ nerve, that runs alongside the Superior Thyroid Artery, is lesioned, it may affect the ____________ muscle which is responsible for tensing the vocal cords to elevate pitch when vocalizing.

Answer 27

External Laryngeal nerve;

Cricothyroid muscle

Question 28

Define the quadrangular membrane and conus elasticus.

Answer 28

Quadrangular membrane = tipped-up epiglottis to the inferior free margin that is the vestibular ligament (false vocal fold)
Conus elasticus = partition between cricoid cartilage and thyroid cartilage, in which the superior free margin is the true vocal chord

Question 29

How does the movement of the vocal ligaments relate to phonation?

Answer 29

Drawing vocal ligaments closer to the midline while expelling air across them creates the vibrations to start phonation.

Question 30

Define the location of the posterior cricoarytenoid muscles as well as their action and innervation.

Answer 30

Posterior cricoarytenoids form the back of the cricoid cartilage and attach to the muscular processes. They are innervated by the recurrent laryngeal branch of the vagus nerve to ABDUCT the vocal folds during inhalation.

Question 31

Describe the location of the Lateral Cricoarytenoid muscles, as well as their action and innervation.

Answer 31

These muscles are located anterolateral to the cricoid process. They are innervated by the External laryngeal nerve and ADDUCT the vocal folds to narrow the opening. This results in whispering.

Question 32

Describe the action and innervation of the Cricothyroid muscles.

Answer 32

These muscles TENSE the vocal folds (by changing the cord length) to elevate PITCH. While contracting, the thyroid cartilage moves forward as the cricoid remains stable. They are innervated by the External laryngeal nerve.

Question 33

Describe the function and innervation of the Vocalis muscles.

Answer 33

These muscles RELAX the vocal folds and attach DIRECTLY to the vocal chords. They function to resonate these chords and are innervated by the Recurrent Inferior Laryngeal Nerve (below the vocal fold).

Question 34

What does the Internal Laryngeal nerve innervate and where?

Answer 34

This nerve relays primary sensation of the cough reflex, and innervates mucosa above the vocal fold.

Question 35

A thyroidectomy endangers the _______ ______ nerve. If its damaged the vocal folds aren’t able to ________ resulting in a whisper.

Answer 35

Recurrent Laryngeal nerve;

Resonate