17-A Pharynx and Oral Cavity

Question 1

List the features of the oral cavity (5) both within and functionally associated with the mouth

Answer 1

teeth and muscles of mastication; salivary glands, buccinator muscle (keep food out of vestibule) and tongue surface and muscles

Question 2

What are the boundaries of the oropharynx?

Answer 2

anteriorly by the tongue, posteriorly by the pharyngeal constrictors and extending down to the epiglottis inferiorly and to the soft palate superiorly

Question 3

The tonsillar fossa is formed by muscular arches of which two muscles? (how are they innervated)

Answer 3

palatoglossus and palatopharyngeus muscles, the fossa contains the palatine tonsils (CN X)

Question 4

Where do the sublingual and submandibular glands open into the mouth?

Answer 4

sublingual onto the floor of the mouth through one duct near the frenulum, submandibular several small ducts along the base of the tongue

Question 5

What types of fibers does the lingual nerve carry?

Answer 5

somatosensory, special sensory (taste via the chroda tympani fibers ) and pre and post sympathetic to submandibular and sublingual glands

Question 6

Where are the lingual artery and hypoglossal nerve in relation to the hypoglossal muscle from the lateral view?

Answer 6

the hypoglossal will be lateral to the muscle, while the lingual artery will be deep tot eh hypoglossus muscle

Question 7

Describe the circuitry that activates the salivary glands.

Answer 7

input arrives via CN VII, IV and X and goes to the nucleus solitarius; the inferior salivary nucleus sends fibers via the lesser petrosal, otic ganglion and via the auricular temporal (V3) to the parotid, the superior salivatory nucleus sends fibers via the chorda tympani in the lingual nerve to the submandibular ganglion and to the submandibular and sublingual glands

Question 8

All the extrinsic muscles of the tongue are innervated by the hypoglossal except this muscle

Answer 8

the palatoglossus is innervated by CN X

Question 9

Name the 4 extrinsic muscles of the tongue and their motions.

Answer 9

palatoglossus (elevate tongue and palate), styloglossus,(retract tongue) hyoglossus (flatten tongue) and genioglossus (protrude tongue)

Question 10

What are the borders of the nasopharynx?

Answer 10

lies behind the nasal cavity, above the soft palate NOTE the auditory tube opens here

Question 11

What landmarks define the length of the laryngopharynx?

Answer 11

extends from the epiglottis to the cricoid cartilage

Question 12

Name the three pairs of tonsils and where they can be found

Answer 12

pharyngeal tonsils (adenoids) in the posterior nasopharynx; palatine tonsils in the palatine fossa in in the posterior lateral mouth and the lingual tonsils on the back of the tongue (the only one that persists to adulthood)

Question 13

Name 3 structures that are associated with the naspharynx soft palate.

Answer 13

auditory tubes open, the levitator veli palatini ( CN V V3 and tensor veil palatini (CN X) seal off the nasophrynx by elevating the soft palate

Question 14

Contrast the actions of the levitator veli palatini and the tensor veli palatini.

Answer 14

the levitator (positioned more medially) lifts the plalate and the tensor causes the palate to be more rigid (positioned laterally)

Question 15

Where do the superior constrictors originate and insert?

Answer 15

insert on the posterior neck middle constrctor and lower skull and inserts on the pteromandibular raphe

Question 16

Where do the middle constrictors originate and insert?

Answer 16

attached posteriorly to the superior and inferior constrictors and anteriorly to the hyoid muscle

Question 17

Where do the inferior constrictors originate and insert?

Answer 17

posteriorly the middle constrictor and anteriorly the thyroid and cricoid cartilages NOTE: this portion of constrictors includes the UES

Question 18

What are the nerve components of the pharyngeal plexus (important for gag reflex)

Answer 18

CN IX is sensory to the pharynx and CN X is the motor to all the muscles of the pharynx except the stylopharyngeus

Question 19

What are the pharyngeal muscles’ role in swallowing?

Answer 19

constrictors contract in sequence as we swallow while supra hyoid muscles help to raise and protrude the hyoid bone

Question 20

Describe a regions in the laryngiopharynx that are important because food and foreign objects can get stuck.

Answer 20

the vallecula are depressions in the front of the epiglottis and commonly a site of trapped food, the piriform recesses serve as gutters to channel food to the esophagus

Question 21

What are the important actions of the soft palate and hyoid during swallowing?

Answer 21

voluntarily we raise our pharynx and elevate the soft palate and then involuntarily the constrictors contract and supra hyoid muscles elevate the hyoid as the UES opens and the food lowers

Question 22

Name the fascia that exits between the skull and the superior constrictors.

Answer 22

pharynygobasilar fascia

Question 23

What is a Zenker’s diverticulum?

Answer 23

it is an out pocketing of the mucosa that due to excessive pressure is pushed outside the constrictor muscle (herniated)

Question 24

Where does the palatopharyngeus originate and insert?

Answer 24

the palatopharyngeus runs vertically from the hard palate to the posterior border of the lamina of the thyroid cartilage and the side of the pharynx and esophagus