Pharynx

Question 1

Outline the boundaries of the pharynx superiorly to inferiorly and anteriorly to posteriorly.

Answer 1

Superior: base of skull
Inferior: esophagus
Anterior: Incomplete w/ communications with the nasal, oral, and laryngeal cavities
Posterior: vertebral column

Question 2

When you look into a patient’s throat, what part of the pharynx do you visualize?

Answer 2

oropharynx

Question 3

What structures can be found in the nasopharynx?

Answer 3

• pharyngeal recess
• auditory tube opening (ostia)
• torus tubarius
• salpingopharyngeal fold, which covers…
• salpingopharyngeus
• pharyngeal tonsils (adenoids)
• tubal tonsils

Question 4

What is Waldeyer’s ring of lymphoid tissue? What tonsils make it up? Where are these tonsils
located?

Answer 4

Waldeyer’s ring of lymphoid tissue serves as protection against bacteria and other harmful things that enter our nose and mouth before they pass through the pharynx. It is made up of:

• pharyngeal tonsils (roof/posterior wall of the nasopharynx)
• tubal tonsils (located on torus tubaris)
• lingual tonsils (root of tongue)
• palatine tonsils (in tonsillar fossa between palatoglossal arch and palatopharyngeal arch)

Question 5

How is the tongue related to the epiglottis and what anatomical connections tether the two
structures together?

Answer 5

The tongue is connected to the epiglottis via the median and lateral glosso-epiglottic folds. The epiglottis is postero-inferior to the tongue.

Question 6

How does the laryngopharynx anatomically relate to the larynx? Is it located anterior, posterior?

Answer 6

The laryngopharynx is posterior and slightly superior to the larynx.

Question 7

What 4 layers make up the pharyngeal wall? Which layer can be seen in isolation superior to the
superior constrictor muscle from the back of the pharynx?

Answer 7

1) Mucosa
2) Pharyngeobasilar fascia
3) Muscular layer
4) Buccopharyngeal fascia
The pharyngeobasilar fascia can be seen in isolation superior to the superior constrictor muscle from the back of the pharynx.

Question 8

What passes through the gap between superior and middle pharyngeal constrictor?

Answer 8

stylopharyngeus muscle and glosso-pharyngeal nerve

Question 9

Why do you need to elevate the pharynx and larynx during swallowing?

Answer 9

The pharynx and larynx must be elevated in order for the epiglottis to properly close off the entrance to the larynx during swallowing.

Question 10

What contributes to the pharyngeal plexus of nerves?

Answer 10

The vagus nerve gives the motor component and the glossopharyngeal nerve gives the sensory component.

Question 11

What is the motor innervation to the pharynx? What is the exception to this rule?

Answer 11

The vagus nerve supplies motor innervation to all pharyngeal muscles except the stylopharyngeus, which is innervated by the glossopharyngeal nerve which runs with the muscle.

Question 12

What are the three divisions of the pharynx and what are their boundaries?

Answer 12

• Nasopharynx: extends from choanae (opening into nasal cavity) down to inferior tip of uvula. Its roof = skull base and floor = soft palate
• Oropharynx: begins at inferior edge of uvula, extending down to upper border of epiglottis. It is bounded anteriorly by the root of the tongue.
• Laryngopharynx: extends from upper border of epiglottis (level of hyoid bone) to inferior edge of cricoid cartilage (level of C6). After that point, becomes continuous with the esophagus.

Question 13

What are choanae? What 2 anatomical areas do these openings communicate between? What bony structure separates the right and left choanae?

Answer 13

There are 2 choanae–one on either side of the nasal septum–that serve as doorways into the nasopharynx from the nasal cavity. They serve as extensions of the nasal cavity and thus have respiratory function.

Question 14

What is the auditory tube and what is its function? What muscles act on it and why are they necessary?

Answer 14

The openings of the auditory tubes (eustachian tubes or pharyngo-tympanic tubes) provide communication between the nasopharynx and the tympanic (middle ear) cavity. Function of the auditory tubes are to equalize pressure of external ear with that of the middle ear.

The salpingopharyngeus muscle (covered by salpingopharyngeal fold) pulls down on the torus tubarius during contraction, which opens up the auditory tubes during swallowing to equalize pressure (think of being on airplane).

Question 15

What are the fauces? What are the pillars of the fauces? What is the space between them called? What is located in this space?

Answer 15

The fauces is the space between the oral cavity and the pharynx. Bounded superiorly by the soft palate, inferiorly by the root of the tongue, and laterally by two arches, or “pillars” of the fauces: the palatoglossal (anterior) and palatopharyngeal (posterior) arches.
Tonsilar fossa (triangular recess) is the space between these 2 arches where the palatine tossil is located

The space between the pillars

Question 16

What is the laryngeal inlet?

Answer 16

The doorway between the larynx and the laryngopharynx division of pharynx. When you breathe in air, it goes through the laryngeal inlet in order to get to the respiratory tract.

Question 17

What are the piriform recesses and where are they located? What structures are located here and why is that clinically relevant?

Answer 17

Depressions on either side of the laryngeal inlet. They are bounded by the laryngeal cartilages (so span the length of the laryngopharynx).

They contain (2) nerves: branches of internal laryngeal and inferior laryngeal (continuation of recurrent laryngeal n). This is clinically important because if a foreign body were to lodge in a piriform recess, it could potentially injure these nerves.

Question 18

What is the function and innervation of the pharyngeal constrictor muscles?

Answer 18

The pharyngeal constrictor muscles all contract involuntarily from superior to inferior, propelling food into the esophagus.

*All pharyngeal muscles, except Stylopharyngeus (a longitudinal muscle) are innervated by the Pharyngeal branch of the vagus n. The Inferior constrictor also receives some innervation from the external and recurrent laryngeal branches of the vagus.

Question 19

What is the function of the longitudinal pharyngeal muscles (palatopharyngeus, styloharyngeus, salpingopharyngeus)?

Answer 19

The longitudinal muscles all elevate the pharynx and larynx during swallowing and speaking. (Pull larynx up so you don’t aspirate objects as you’re swallowing)

Question 20

What type of fibers do you find in the pharyngeal branch of CN X?

Answer 20

The pharyngeal branch of X carries both somatic motor and somatic sensory. Motor to muscles of soft palate and all pharyngeal muscles (except Stylopharngeus = IX). Sensory to lower pharynx)

Question 21

Distinguish the sensory innervation to each division of the pharynx.

Answer 21

Nasopharynx = V2 (Maxillary)
Oropharynx = CN IX (Glossopharyngeal)
Laryngopharynx = CN X (Vagus)

Question 22

Outline the 3 stages of swallowing and what muscles are active during each.

Answer 22

1st = Oral stage: voluntary initiation where forming bolus with tongue against hard palate. 2 main muscles = Suprahyoid, fixes the hyoid bone, and Tongue, forces bolus into oropharynx

2nd = Pharyngeal stage: reflexive closure of airway. The Levator veli palatini and Tensor veli palatini contract to seal oropharynx from nasopharynx, preventing regurgitation into nose. Then, longitudinal pharyngeal mm and suprahyoid contract to close laryngeal inlet by epiglottis.

3rd = Pharyngo-esophageal stage: reflex transport. Pharyngeal constrictor mm contract from sup to inf to propel bolus into esophagus and stomach.

Question 23

What are the attachments of each pharyngeal constrictor muscle?

Answer 23

All 3 constrictor muscles attach posteriorly to the pharyngeal raphe.

• Superior constrictor: anterior = pterygomandibular raphe (close relationship with Buccinator m); superior = pharyngeal tubercle of the occipital bone
• Middle constrictor: anterior = stylohyoid ligament and hyoid bone
• Inferior constrictor: anterior = oblique line of thyroid cartilage and the cricoid cartilage