GA - Conta - Pharynx/Soft Palate/Salivary Glands - 2/23 Flashcards
Where does the pharynx begin? Where does it end? Which of the constrictor muscles lies immediately posterior to the buccinator?
The pharynx extends from the occipital bone down to the level of the 6th vertebra, at the inferior border of the cricoid cartilage; here it is continuous with the esophagus. The superior pharyngeal constrictor muscle lies posterior to the buccinators muscle.
What is the collective function of the three constrictor muscles? What is their nerve supply?
They decrease the lumen of the pharynx; when used in sequence, they propel the food bolus from the oral cavity to the esophagus. Innervation is from the pharyngeal plexus.
What is the collective function of the three longitudinal muscles? What is their nerve supply? What is their importance during swallowing?
The longitudinal muscles (stylopharyngeus, salpingopharyngeus and palatopharyngeus) collectively elevate the pharynx and larynx during swallowing and phonation. Innervation is from the pharyngeal plexus, except the stylopharyngeus muscle, which is innervated by branches of CN IX)
Where are the pharyngeal tonsils (adenoids) located relative to auditory tube? Why is the relationship important?
They are located posterior and superior to the opening of the auditory tube. If enlarged, they may block air passage, impair hearing and/or promote spread of infections to the middle ear.
Where is the oropharynx relative to the oral cavity?
The oropharynx lies beneath the soft palate and anterior to the epiglottis, at the posterior aspect of the oral cavity.
When a surgeon is performing a tonsillectomy, what landmarks are important? What problems can arise during the surgery or postoperatively?
The palatoglossal and palatopharyngeal arches are important landmarks, as they delineate the relative location of the tonsillar bed. Surgical or post-surgical complications include extensive bleeding from damage to branches of the ascending pharyngeal and facial arteries that lie in the tonsillar bed. Edema in the region may impinge on the underlying glossopharyngeal nerve (CN IX), causing temporary loss of taste.
Where are the piriform recesses located? If your patient had a portion of a fish bone lodged in one of these areas, what are the potential clinical consequences?
The piriform recesses or sinuses are located bilaterally in the laryngopharynx, between the aryepiglottic folds and the thyrohyoid membrane and thyroid cartilage. Foreign bodies may become lodged here, abrading the underlying mucosa and damaging branches of the internal and recurrent laryngeal nerves, which reside in this region.
What muscles make up the soft palate? What is their innervation? What is the function of the soft palate?
Soft palate muscles: levator veli palatini, tensor veli palatini, palatoglossus, palatopharyngeus and musculus uvulae. All muscles are innervated by branches of the pharyngeal plexus (pharyngeal branches of Vagus), except for the tensor veli palatine, which is innervated by a branch of the mandibular division of the trigeminal nerve (V3). The soft palate is important during swallowing; it plays a key role in closing off the nasopharynx during transfer of the food bolus from the oral cavity to the pharynx.
What three events must occur before the constrictor muscles act during the second stage of swallowing? What is the reason for each of these?
i. Closing off of nasopharynx by tensing soft palate prevents bolus from regurgitating into nasopharynx/nasal cavities
ii. Elevation of pharynx and larynx by contracting suprahyoid muscles and longitudinal pharyngeal muscles aids in hiding airway under posterior tongue and epiglottis; the glottis is closed
iii. Retroflexion of epiglottis helps guide food bolus away from laryngeal inlet and into the laryngopharynx.
What group of muscles controls the descent of the larynx during the third stage of swallowing?
Infrahyoids.
What component fibers are present in the branch of the glossopharyngeal nerve found in the tonsillar bed? In the tympanic branch?
The glossopharyngeal nerve in tonsillar bed contains somatic motor fibers to the stylopharyngeus muscle, general sensory fibers from the mucosa of the pharynx, tonsils, soft palate and posterior 1/3 of tongue, and special sensory from the posterior 1/3 of tongue. The tympanic branch of the glossopharyngeal nerve contains general sensory fibers from the mucosa of the tympanic cavity, auditory tube and mastoid air cells. Once outside the tympanic cavity, it continues as the lesser petrosal nerve, which contains preganglionic parasympathetic fibers that go to the otic ganglion.
What cranial nerves need to be intact in order for swallowing to occur without incidents?
CN V3, 7, 9, 10 and 12.
