Pharynx Flashcards
The pharynx extends from what level superiorly to where inferiorly?
from the base of the skull to the level of cervical vertebra 6 where the esophagus begins
What are the sections of the pharynx?
nasopharynx, the oropharynx and the laryngopharynx
Which part of the pharynx do air passages and food passages cross?
the oropharynx
The nasopharynx extends from what levels in the body?
from the base of the skull to the level of the palate
Does the nasopharynx have any food related function?
No, just respiratory
Superiorly, the posterior wall of the oropharynx attaches to what?
Superiorly, the posterior wall of the nasopharynx abuts against the occipital bone where it attaches to the pharyngeal tubercle
What tonsils line the upper aspect of the nasopharynx?
the pharyngeal tonsils, an important part of the immune system’s early warning system.
Swelling of this tonsil (adenoids) can make passage of air through the nasopharynx difficult
The entrances from the the nasal cavities into the pharynx are called what?
the choanae, the two oval openings to either side of the nasal septum
Access to the nasopharynx and nasal cavity from the oropharynx can be closed off by action of what?
tensors and elevators of the palate and the palatopharyngeal sphincter of the superior constrictor
What is the torus tubarius?
an elevation where the mucosa covers the cartilaginous portion of the auditory tube that penetrates the pharynx.
What vertical fold of mucosa extends inferiorly from the posterior border of the torus tubarius?
salpingopharyngeal fold
What muscle does the salpingopharyngeal fold cover?
it overlies the salpingopharyngeus muscle
What is a main function of the salpingopharyngeus muscle?
to pull on the cartilage of the auditory tube, which allows the auditory tube to open and equalize the pressure on both sides of the ear drum. This occurs naturally during swallowing.
The oropharynx extends from what levels in the body?
from the palate to the level of the hyoid bone and the upper limit of the epiglottis, which are at a similar level
Which tonsils can be found at the function of the oral cavity and the oropharynx?
the palatine tonsils
The inferior continuation of the salingopharyngeal folds of the nasopharynx is called what?
the palatopharyngeus folds, (covers the palatopharyngeus muscle)
What spans between the palatopharyngeal fold and the epiglottis?
the pharyngoepiglottic fold
What muscle attaches to the superior border of the thyroid cartilage just deep to the pharyngoepiglottic mucosal fold?
The stylopharyngeus muscle attaches to the superior border of the thyroid cartilage just deep to this mucosal fold.
What tonsils can be found in the salpingopharyngeal folds?
the tubular tonsils
Which tonsils line posterior margin of the nasopharynx at the cavity
the lingual tonsils (flanked on the lateral sides by the palatine tonsils)
What is the the cricopharyngeous?
the lower portion of the inferior constrictor that attaches to the cricoid cartilage.
What is the function of the cricopharyngeous?
The cricopharyngeous serves as the upper esophageal sphincter.
What muscle originates exterior to the superior and middle pharyngeal constrictor muscles but pierces through them to insert internally?
the stylopharyngeous m.
What is the role of the longitudinal muscles (salpingopharyngeous, stylopharyngeous, and palatopharyngeous)?
they help to raise the larynx and wall of the pharynx during swallowing.
What are the posterior layers surround the pharynx from most internal to most external?
mucosa, pharyngobasilar fascia (submucosa), the circular muscles (and in some places the longitudinal muscles), and the buccopharyngeal fascia
The pharyngobasilar fascia extends from what levels in the body?
the base of the skull to the hyoid bone, and thins out below the hyoid bone
What levels in the body does the buccopharyngeal fascia run from?
covers the entire pharynx from the base of the skull and extends out over the buccinator muscles in the face. Inferiorly it extends into the mediastinum posterior to the esophagus.
Where is the most superior space caused/created by the pharyngeal muscles?
between the superior border of the superior constrictor and the base of the skull
What fills in the superior gap of the constrictor muscles?
pharyngobasilar fascia
What passes through the space caused by the between the superior border of the superior constrictor and the base of the skull?
The cartilaginous portion of the auditory tube, the levator veli palatini, the ascending palatine artery, and the ascending pharyngeal artery all pass through this gap
The gap between the superior and middle pharyngeal muscles is filled in by what?
pharyngobasilar fascia
What passes through the gap created by the superior and middle constrictor muscles?
The stylopharyngeus muscle passes through this gap to get to its insertion on the inner surface of the pharyngeal wall and the thyroid cartilage. The glossopharyngeal nerve also passes through this gap and under the pharyngeal tonsil to end in the posterior tongue. The lingual artery also passes toward the tongue in this gap.
Where does pharyngobasilar fascia thin out?
Below the hyoid bone
What passes through the gap created by the middle and inferior constrictors?
The internal branch of the superior laryngeal nerve and the superior laryngeal artery pass through an aperture in the thyrohyoid membrane to enter the larynx.
What fills in the gap between the middle and inferior constrictors?
thyrohyoid membrane
What passes through the gap created by the inferior constrictor and the esophagus?
the recurrent laryngeal nerve (which almost immediately changes its name to inferior laryngeal nerve) and the laryngeal branch of the inferior thyroid artery pass
What covers the gap between the inferior constrictor and the esophagus?
This area is covered with buccopharyngeal fascia, which forms a continuous external layer covering the pharynx starting superiorly at the base of the skull.
What structures form the pharyngeal plexus?
The glossopharyngeal nerve provides several pharyngeal branches that join with branches of the vagus and branches from the superior cervical ganglion to form the pharyngeal plexus
What functional components are in the pharyngeal plexus?
a network of combination of sensory (GSA) and motor fibers (BE)
What BE components does the glossopharyngeal nerve supply in the pharyngeal plexus?
stylopharyngeous m.
What GSA components does the glossopharyngeal nerve supply in the pharyngeal plexus?
Upper 2/3 of pharynx- mainly to the nasopharynx and oropharynx
What BE components does the vagus nerve supply in the pharyngeal plexus?
pharyngeal constrictors,
What GSA components does the vagus nerve supply in the pharyngeal plexus?
Lower 1/2 of pharynx- mainly the laryngopharynx, palatopharyngeous, and salpingopharyngeous
What are the 5 sources of blood supply to the pharynx?
1) the ascending pharyngeal artery (a direct branch of the external carotid),
(2) the ascending palatine artery (a branch of the facial artery) and tonsillar branches of the facial artery,
(3) the descending palatine and pharyngeal branches of the maxillary artery,
(4) Un-named branches from the lingual artery, and
(5) muscular branches of the inferior thyroid artery (from the thyrocervical trunk).
The veins of the pharynx form one plexus on its external surface and another between pharyngeal musculature and pharyngobasilar fascia. Where do they drain do?
Some of the pharyngeal veins drain into the pterygoid plexus. Also drains into the internal jugular vein via communication with facial and thyroid veins.
Where do retropharyngeal nodes lie?
deep to the superior constrictor muscle between it and the vertebral fascia and vertebral column
Where do the retropharyngeal nodes drain?
into the chain of deep cervical nodes located on the posterior aspect of the internal jugular vein
What is the primary route of the nasopharynx?
primarily into the jugulodigastric node at the top of the deep cervical chain
Where is the jugulodigastric node located?
just superficial to the point where the posterior digastric belly cross superficial and posterior to the external jugular vein. Located under the ear near the back of the mandible
The deep cervical chain combines with what to form the right/left jugular trunks?
drainage from the infrahyoid nodes
What does the left jugular trunk drain into? The right jugular trunk?
left- into the thoracic duct
right- into the right lymphatic duct
Where is the retropharyngeal space?
directly posterior to the pharynx, between it and the vertebrae, and runs from the base of the skull clear down to the mediastinum.
The borders of which two fascia make up the retropharyngeal space?
It is bounded anteriorly by buccopharyngeal fascia, and posteriorly by prevertebral fascia
How can infection spread through the lateral and retropharyngeal spaces?
Infections can pass from gums, teeth, tongue, and pharynx to the lateral pharyngeal space. The lateral pharyngeal space communicates with the retropharyngeal space, from which infections can continue to spread to the base of the skull or into the mediastinum
What are the phases of swallowing?
1) Oral Phase
2) Oral Propulsive Phase
3) Pharyngeal Phase
4) Esophageal Phase
What happens in the oral phase?
Mastication and bolus formation
What happens in the oral propulsive phase?
Closure of the nasopharynx and propulsion of the bolus into the pharynx by the tongue
What happens in the pharyngeal phase?
The pharynx is pulled upward and anterior and widened and shortened by the supra hyoid and longitudinal laryngeal muscles, causing access to the larynx to be disrupted. Chewing, breathing, and coughing pathways are closed. Waves of pharyngeal muscle contraction move the bolus through the piriform recess and past the cricopharyngeal sphincter into the esophagus. The cricopharyngeal sphincter relaxes to allow passage of the bolus, then closes to prevent regurgitation
What happens in the esophageal phase?
waves of peristalsis propel the bolus through the esophagus to the stomach
What is the method of neural stimulation/regulation of the pharyngeal phase of the swallowing reflex?
Sensory receptors on the tongue and elsewhere sense a properly prepared bolus and signal the brainstem via afferent CN IX and X fibers which synapse at the ‘Nucleus tractus solitarius’ and relay the signal to the ‘Nucleus ambiguus’ that sends efferent signals (via CN IX and X again) to the parts of the pharynx and esophagus to stimulate/regulate swallowing
How does the gag reflex work?
sensory receptors in the pharynx and surrounding tissue recognize an unprepared, abnormal bolus. The motor limb of the reflex causes elevation of the soft palate and bilateral constriction of the constrictor muscles, causing ejection of the pharynx contents into the oral cavity.
What are some conditions that can interfere with the pharyngeal phase of swallowing?
- strokes
- neurological disorders, such as Parkinson’s, multiple sclerosis, alzheimer’s, or just by aging
- infections
- pharyngeal diverticula
- foreign bodies
Swallowing disorders (oropharyngeal dysphagia) can happen at any age, but are most often reported by older people. Oropharyngeal dysphagia can be caused by anything that affects the nerves and/or mucscles in the oral cavity, pharynx, or esophagus
What is Zenker’s Diverticulum?
- Outpouching of mucosa through an area of weakness between the cricopharyngeus and lower inferior constrictor
- Diagnosis confirmed by contrast radiography
2:100,000, 2/3 male, 70s-80s, 94% with pharyngeal pouches have GERD and/or hiatal hernias
