Exam 4 Pharynx

Question 1

Overview of Pharynx

• What is it a common passageway for?
• Where is it located?
• What does it communicate with?
• What are its three subdivisions?

Answer 1

• Common passageway for digestive and respiratory systems.
• Extends from base of skull and becomes continuous with esophagus (at level C6). Lies anterior to cervical vertebrae and separated by prevertebral fascia.
• Communicates anteriorly with nasal cavity, oral cavity, and larynx
• Divided into nasopharynx, oropharynx, and laryngopharynx.

Question 2

Nasopharynx

• Where is it located? (Roof and floor)
• What does it communicate with and through what openings?
• Features of nasopharynx

Answer 2

• Most superior part of pharynx; Posterior to nasal cavity and superior to soft palate.
  
  • Roof is base of skull, floor is soft palate
• Communicates with:
  
  • Nasal cavity via choanae
  • Oropharynx via pharyngeal isthmus (b/w posterior wall of pharynx and uvula)
• Features: Contains slit like posterolateral extension just superior to pharyngeal isthmus called pharyngeal recess.

Question 3

Auditory (Eustachian, pharyngotympanic) tube

• What does it connect?
• Where is it located?
• What is its function?
• Parts (2)
  
  • Where are they located and what is their function?

Answer 3

• Connects middle ear cavity and nasopharynx via ostia (openings).
  
  • This connection can allow infection to spread along its length.
• Extends posteriorly, laterally and superiorly
• Function: Equalizes pressure of external air with that of middle ear.
• Parts:
  
  • Cartilaginous part: Lies on inferior aspect of skull in groove b/w greater wing of sphenoid bone and petrous part of temporal bone.
    
    • Remains closed except when swallowing or yawning to prevent excessive pressure in middle ear.
  • Osseous part: Located withing petrous temporal bone b/w middle ear and cartilaginous tube.

Question 4

What is the torus tubarius?

Answer 4

• Cartilaginous elevation surrounding ostia of auditory tubes
• Located anterior to pharyngeal recess

Question 5

What is the salpingopharyngeal fold? What does it cover and what is its function?

Answer 5

• Mucosal fold (Pink) attached to torus tubarius (Green)
• Covers salpingopharyngeus muscle (Black)
  
  • Elevates pharynx and larynx during swallowing and speaking.

Question 6

What lymph nodes make up Waldeyer’s ring?

Where are they located?

Answer 6

• Pharyngeal tonsils (Blue): Located in roof of posterior wall of nasopharynx
  
  • Called adenoids when enlarged
  • Infection and inflammation can block opening of auditory tube
• Tubal tonsils (Green): Located on torus tubarius
• Lingual tonsils (Purple): Located on root of tongue
  
  • Give tongue irregular cobblestone appearance
• Palatine tonsil (Red): Located in tonsillar fossa between palatoglossal arch and palatopharyngeal arch

Question 7

Oropharynx

• Where is it located (Inferior to, superior to, posterior to)?
• What does it communicate with and through what opening?
• What is it laterally bounded by?

Answer 7

• Intermediate region of pharynx
• Located inferior to soft palate, superior to upper edge of epiglottis, posterior to oral cavity (root of tongue).
• Communicates with oral cavity via oropharyngeal isthmus (isthmus of fauces)
• Bounded laterally by by palatoglossal arch (Purple) (anterior pillar of fauces) and palatopharyngeal arch (Blue) (posterior pillar of fauces)
  
  • Tonsillary fossa in between (Yellow): contains palatine tonsil

Question 8

How is the epiglottis attached to the tongue?

What depressions are on either side of middle connection? Why is it clinically relevant?

Answer 8

• Epiglottis attached to tongue by median glosso-epiglottic fold and lateral glosso-epiglottic folds
• Depressions called valleculae on either side of median glosso-epiglottic fold
  
  • Site where foreing objects can get lodged.

Question 9

Laryngopharynx

• Where is it located?
• What does it communicate with and via what opening?
• What is the piriform recess?
• What nerves are vulnerable to injury if a foreign body lodges into piriform recess.

Answer 9

• Extends from upper border of epiglottis (at level of hyoid bone) to inferior edge of cricoid cartilage (where it is continuous with esophagus).
• Communicates anteriorly with larynx via laryngeal aditus (laryngeal inlet).
• Piriform recess: Depression of laryngopharynx on either side of laryngeal inlet.
• Nerves vulnerable: Internal laryngeal and recurrent laryngeal.

Question 10

4 layers that make up the pharyngeal wall

What kind up epithelium is lining pharynx?

Answer 10

• Mucosa
• Pharyngeobasilar fascia: submucosa separating mucosa from muscular wall
• Muscular layer: Consists of 3 overlapping pharyngeal constrictor muscles and 2 pairs of elevators of pharynx
• Buccopharyngeal fascia: Surrounds muscular layer of pharynx to allow pharyngeal expansion and mobility
• Epithelium: Either respiratory (pseudostratified columnar) or stratified squamous (lining digestive tract)

Question 11

Superior, Middle, Inferior Constrictor Muscle

• Function
• Attachments
  
  • Anterior
  • Posterior
  • Superior
  • Inferior
• What passes between superior and middle constrictors?

Answer 11

• Function: Contract involuntarily superior to inferior to move food into esophagus
• Superior Constrictor (Blue):
  
  • Attached anteriorly to pterygomandibular raphe
  • Attached posteriorly to pharyngeal raphe
  • Attached superiorly to pharyngeal tubercle of occipital bone
    
    • Lateral deficiency closed off my pharyngobasilar fascia (Yellow) (perforated by auditory tube and levator veli palatini)
• Middle Constrictor (Black):
  
  • Attached anteriorly to stylohyoid ligament and hyoid bone
  • Attaches posteriorly to pharyngeal raphe
  • Stylopharyngeus muscle (Purple) & glossopharyngeal nerve pass through gap b/w superior and middle constrictors
• Inferior Constrictor (Green)
  
  • Attached anteriorly to oblique line of thyroid cartilage & cricoid cartilage
  • Attached posteriorly to median pharyngeal raphe

Question 12

Inner longitudinal layer of pharyngeal muscles:

Palatopharyngeus

Stylopharyngeus

Salpingopharyngeus

• Function of all three?
• Where are they located?
• What covers them? (if applicable)

Answer 12

• Function: Elevate the pharynx and larynx during swallowing and speaking
• Palatopharyngeus (Blue)
  
  • Extends from soft palate down into lateral walls of pharynx
  • Covered by palaopharyngeal arch/fold
• Stylopharyngeus (Purple)
  
  • Extends from styloid process of temporal bone to lateral walls of pharynx
  • Passes between internal and external carotids/between superior and middle constrictors
• Salpingopharyngeus (Black)
  
  • Extends from cartilaginous part of auditory tube to lateral wall of pharynx
  • Covered by salpingopharyngeal arch/fold

Question 13

Blood supply and venous drainage of pharynx

• What supplies the upper pharynx?
• What supplies the lower pharynx?
• What drains the pharynx?
  
  • What do these veins drain into?

Answer 13

• Upper pharynx supplied by ascending pharyngeal artery, ascending palatine and tonsillary branches of facial artery.
• Lower pharynx supplied by superior thyroid artery.
• Pharyngeal plexus of veins drains pharynx (located in buccopharyngeal fascia)
  
  • Drains into pterygoid plexus of veins, internal jugular vein, and facial veins.

Question 14

Innervation of pharynx

• What provides motor innervation?
• What provides sensory innervation?

Answer 14

• Motor innervation supplied by pharyngeal branch of vagus nerve.
  
  • EXCEPT stylopharyngeus supplied by glossopharyngeal nerve
• Sensory innervation:
  
  • Nasopharynx supplied by V2
  • Oropharynx supplied by glossopharyngeal nerve
  • Laryngopharynx supplied by vagus nerve.