Lab 2: Pharynx and Oral Cavity Flashcards
describe the three divisions of the pharynx
It is divided into a nasopharynx, which has a respiratory function; an oropharynx which has a digestive function, and a laryngopharynx
describe the function of the pharynx
pharynx is an incomplete muscular tube that serves as a common pathway for the respiratory and digestive tracts
where are the pharyngeal tonsils located, and what are they made up of?
pharyngeal tonsils are located in the posterior wall of the nasopharynx, these are accumulations of lymphoid tissue
how do we call pharyngeal tonsils when they are enlarged?
they are called adenoids, when they are enlarged usually due to an infection.
what are the consequences of enlarged pharyngeal tonsils, which structures are they capable of blocking?
enlarged tonsils
- block the passage of air (breathing through mouth helps)
- may block the opening of the Eustachian tube, impair hearing, or promote spread of bacteria into the middle ear
describe it, as well as the role of the salpingopharyngeal fold ?
it is a mucous membrane fold containing the salpingopharyngeus muscles. It helps open the Eustachian tube during swallowing to equalize air pressure between middle ear and nasopharynx
what does the nasopharynx communicate with?
it communicates with the nasal cavity
what does the oropharynx communicate with?
the oropharynx communicates with the oral cavity?
which two mucuous membrane folds define the boundaries of the tonsillar beds?
the palatoglossal and the palatopharyngeal arches
where are the palatine tonsils found? what are they? and what is key about their placement?
palatine tonsils sit within the tonsillar bed of the oropharynx, between the 2 folds. They are accumulations of lymphoid tissues strategically placed at entrance of both tracts to protect body from entry of foreign material via mucosa
what is a a common resolution to persistent inflammation of the tonsils (palatine)?
a tonsillectomy
describe the clinical significance of the tonsillar bed
it contains key vessels and nerves residing in its mucosa such as
- branches of the ascending pharyngeal and facial arteries
- external palatine vein
- glossopharyngeal nerve
* **damage to arteries during a tonsillectomy result in excessive bleeding
where does the glossopharyngeal nerve run ?
it runs on the very thin lateral wall of the pharynx, and may be damaged during surgery - post-operative edema can impinge lead to transient loss of taste
where does the laryngopharynx extend to and from?
Laryngopharynx extends from the upper border of the epiglottis to the lower border of the cricoid cartilage. It communicates with the larynx via the laryngeal inlet on its anterior wall.
where are piriform recesses located? and what is their clinical significance?
piriform recesses are found in the laryngopharynx, these are mucosa lined depressions on either side of the laryngeal inlet. Clinical - food/foreign bodies may become lodged by these recesses,may injure nerves that lie close by (laryngeal n.)
what separates the nasopharynx from the oropharynx?
the soft palate! it s movable muscular fold that attaches to the hard palate.
which 5 paired muscles make up the soft palate? innervation?
- levator veli palatini
- tensor veli palatini
- palatoglossus
- palatopharyngeus
- musculus uvulae
All insert into the palatine aponeurosis. ALL innervated by CN X, except for the tensor veli palatini - innervated by CN III
describe the function of the soft palate muscle contraction
their contraction leads to elevation of the soft palate to close off the nasopharynx during swallowing, preventing nasal regurgitation
describe the 2 layers of the muscles of the pharynx and the muscles defined by them?
the pharynx is divided into a external and and internal layer.
external layer contains circumferentially oriented fibers, these are the superior, middle and inferior constrictors
internal layer contains the longitudinally oriented fibers - these are the stylopharyngeus, the salpingopharyngeus, palatopharyngeus muscles which lie deep to the constrictors.
contraction of the superior, middle and inferior constrictors has what effect? what is their innervation?
It decreases the lumen of the pharynx, which used in sequence helps propel a bolus of food from oral cavity to the esophagus . They are all innervated by CN X, from pharyngeal plexus
muscles of the internal layer function to do what? what is their innervation?
as a group, they elevate the pharynx and the larynx during swallowing and phonation. Innervated by CN X, except for the stylopharyngeus, which is innervated by CN IX
what are three phases of swallowing? which phases are voluntary and involuntary?
1st phase - oral preparatory phase - food molded into compact bolus (voluntary)
2nd phase - pharyngeal phase - delivery of food bolus triggers phase, pharynx goes from being an air channel to a food channel (involuntary)
3rd phase - esophageal phase - food gains entry into the esophagus
name the salivary glands of the pharynx and what their roles are
the salivary glands help with bolus formation, they mositurize and lubricate food prior to pharyngeal swallowing. Include parotid gland, submandibular and sublingual glands.
what is dysphagia?
dysphagia means trouble swallowing
describe the sulcus terminalis
it’s a V shaped groove that divides the anterior 2/3 and the posterior 1/3 of the tongue. it angles to a point called the foramen cecum (embryol remnant)
muscles of the tongue are innervated by
the hypoglossal nerve, CN XII, except for the palatoglossus muscle, innervated by CN X (vagus n.)
sensory and special sensory innervation of the tongue is from?
sensory innervation - lingual nerve ( CNV3 ) and glossopharyngeal nerve (posterior 1/3)
taste - chorda tympani (CN VII) and glossopharyngeal nerve (posterior 1/3)
“palate muscles” are innervated by? except for which?
are innervated by CN X vagus nerve, except for tensor veli patatini m, innervated by V3
“pharyngeal muscles” are innervated by? except for which?
are innervated by CN X vagus nerve, except for stylopharyngeus muscle (CN IX)
“glossus muscles” are innervated by ? except for which?
are innervated by CN 12, hypoglossul nerve, except for palatoglossus n, innervated by CN X
