Flashcards in Posterior pharynx and larynx Deck (66):
The pharynx is a ________ tube that extends from the _______ to the ________ at the level of the ______ vertebrae. Name the 3 parts it consists of.
-nasal cavity to cricoid cartilage at level of 6th cervical vertebrae
-nasopharynx, oropharynx, and laryngopharynx
What 4 things are found on the lateral wall of the nasopharynx?
1. opening of auditory tube
2. levator veli palatini
3. tensor veli palatini
What innervates the mucosa of the nasopharynx?
-pharyngeal nerve, a branch of the maxillary division of V2
-also by branches of glossopharyngeal nerve in the pharyngeal plexus
Describe the position of the nasopharynx
-superior to soft palate and posterior to nasal cavity
Describe the location of the oropharynx
-between the soft palate and tip of epiglottis, posterior to oral cavity
Name 3 things found on the lateral wall of the oropharynx
-palatoglossal arch and palatoglossal muscle
-palatopharyngeal arch and palatopharyngeus muscles
-tonsilar fossa (separates above arches) that contains the palatine tonsil
What crosses the tonsillar fossa?
-lingual branch of the glossopharyngeal nerve (CN IX)
What does the floor of the oropharynx contain and what innervates this structure?
-posterior 1/3 of tongue
-both taste and general sensations from posterior 1/3 of tongue are carried by lingual branches of the glossopharyngeal nerve (CN IX)
Where does the laryngopharynx extend from and to? What does it become continuous with at its ending?
-from epiglottis behind the larynx to the level of the cricoid cartilage
-inferior to cricoid cartilage, the LP is continuous with the esophagus
What does the lateral wall of the laryngopharynx contain? What courses in the walls of this space?
-internal branch of superior laryngeal nerve of the vagus and superior laryngeal artery
What innervates the mucosa of the laryngopharynx?
-internal branch of the superior laryngeal nerve of the vagus
The pharynx consists of skeletal muscles that form an ________ layer and an _________ layer.
-outer circular layer
-inner longitudinal layer
What muscles make up the outer circular layer of the pharynx? Where do they overlap? What do they do? What innervates these muscles?
-superior, middle, and inferior constrictor muscles
-overlap and interdigitate in the posterior midline at the pharyngeal raphe
-constriction of the 3 constrictor muscles propels a bulus through the oropharynx and laryngopharynx during swallowing
What does the inferior constrictor muscle of the pharynx become continuous with and where?
-esophagus at cricoid cartilage
Name the 3 muscles that form the inner longitudinal layer of muscles of the pharynx and their actions
-they act to elevate (shorten) pharynx during swallowing
All of the muscles of the pharynx are innervated by branches of the _____________ through the __________ except for which muscle? What is the innervation of this muscle?
-stylopharyngeus which is innervated by glossopharyngeal nerve (CN IX)
Describe the passage of the stylopharyngeus muscle and glossopharyngeus nerve and the passage of the stylohyoid muscle.
-Stylopharyngeus: pass from medial side of the styloid process anteromedially through the interval between the superior and middle constrictor muscles
-stylohyoidL passes from lateral side of styloid process and splits on its way to the hyoid bone to accomodate passage of the tendon of the digastric
What makes up the pharyngeal plexus and what does this plexus give rise to?
-pharyngeal branches of CN IX and CN X form the plexus
-CN IX supplies sensory component while CN X supplies motor innervation to pharynx
At what vertebral level does the esophagus begin?
Name the structures that enter the esophagus between the skull and superior constrictors, superior and middle constrictors, middle and inferior constrictors, and inferior constrictors and esophagus.
-skull/superior: auditory tube, levator veli palatini muscle, ascending palatine artery
-superior/middle: stylopharyngeus, stylohyoid ligament, glossopharyngeal n (CN IX)
-middle/inferior: internal branch of superior laryngeal nerve of vagus (CN X) and superior laryngeal artery and vein
-inferior/esophagus: inferior laryngeal nerve (recurrent) of CN X and inferior laryngeal artery
What types of fibers does the glossopharyngeal nerve (CN IX) contain?
-skeletal motor axons
-preganglionic parasympathetic axons
-general sensory fibers
How does the glossopharyngeal nerve leave the skull? what does it innervate?
-traverses jugular foramen and its skeletal motor axons innervate a single muscle: stylopharyngeus
-preganglionic parasympathetic axons in CN IX innervate parotid gland
What is the only muscle CN IX innervates?
Describe the course taken by the parasympathetic fibers of CN IX
-these preganglionic axons course in the tympanic nerve and in the lesser petrosal nerve
-lesser petrosal n passes through foramen ovale and synapses in the otic gangliion, located in infratemporal fossa just below foramen ovale
-postganglionic parasympathetic axons from otic ganglion join auriculotemporal nerve (V3 branch) to reach parotid gland
Describe the sensory branches of the Glossopharyngeal nerve: where they arise from and what they innervate.
-innervates mucous membranes on posterior wall of oropharynx and nasopharynx inferior to entrance of auditory tube via pharyngeal plexus (pharyngeal branch)
-lingual branch conveys general sensation and taste from posterior 1/3 of tongue
-tonsillar branch supplies mucosa of palatoglossal and palatopharyngeal arches and intervening tonsillar fossa
-carotid sinus branch innervates carotid body and carotid sinus
What fibers make up the gag reflex and what occurs during this reflex?
-sensory fibers from glossopharyngeal nerve (IX) in oropharyngeal mucosa and motor fibers in vagus nerve
-stimulation of CN IX results in bilateral contraction of pharyngeal musculature and elevation of soft palate
May be pharyngeal tonsillitis lead to otitis media?
-infection can spread along auditory tube into middle ear
If you position yourself at the base of the pharynx, what is posterior and anterior to you?
-anterior: inferior border of cricoid cartilage
-posterior: C6 vertebrae
The nasopharynx has a _______ function. The nose opens into it via 2 large posterior apertures called _____________. The roof and posterior wall of nasopharynx form a continuous surface that lies inferior to 4 things?
-choanae or internal nares
-body of sphenoid bone, basilar part of occipital bone, anterior arch of atlas, body of axis
What is found in the mucous membrane of the roof and posterior wall of the nasopharynx? What is this and what is it called when enlarged?
-pharyngeal tonsil: a collection of lymphoid tissue which is called adenoids when enlarged
The nasopharynx communicates laterally with the tympanic cavity via the __________ (3 names). What is found on the pharyngeal opening to this? What forms this projection?
-hook-like tubal elevation called the torus of the auditory tube; formed by base of the cartilaginous part of the auditory tube
The lymphoid tissue at the opening of the auditory tube is designated as the ___________.
Describe the folds surrounding the torus of the eustachian tube. What is found posterior to fold off of posterior eustachian tube?
-salpingo-pharyngeal fold: vertical fold of mucous membrane that descends from posterior limb of torus to lose itself in pharyngeal wall; it covers the salpingopharyngeus muscle
-laterally directed slit-like recess called pharyngeal recess of fossa of Rosenmuller
-salpingo-palatine fold: small fold descending from anterior margin of torus to soft palate
What is another name for the pharyngeal recess?
-fossa of Rosenmuller
What does the salpingopharyngeus muscle do?
-opens auditory tube during swallowing
Adenoid facies is associated with what? What else can this cause?
-hypertrophy or enlargement of pharyngeal tonsils
-this obstructs passage of air from nasal cavities thru choanae into nasopharynx which makes mouth breathing necessary and in chronic cases, patient developed adenoid facies
-impairment in hearing if nasal obstruction and blockage of pharyngeal orifice of auditory tubes
-infection may spread to tubal tonsils causing swelling and closure of auditory tubes and further to otitis media
5 layers of pharyngeal wall from internal to external
-mucous membrane lining pharynx and is continuous with cambers with which it communicates
-fibrous layer forming pharyngobasilar fascia which is attached to skull
-muscular layer composed of inner longitudinal and outer circular parts
-loose connective tissue layer forming buccopharyngeal fascia
What is the buccopharyngeal fascia continuous with and what does it contain and allow movements of?
-epimysium covering buccinator and pharyngeal muscles
-permits movements of pharynx
-contains pharyngeal plexus of nerves and veins
What are the palatine tonsils? Where are they located?
-2 masses of lymphoid tissue in lateral walls of oropharynx
-each located in triangular cleft called tonsillar sinus between the diverging palatoglossal and palatopharyngeal folds or arches
What covers the medial surface of palatine tonsils? Where does it extend inferiorly, anteriorly, and superiorly? What covers its deep surface?
-mucous membrane with 10-20 crypts that extend deeply into tonsillar structure
-inferiorly invades dorsum of tongue and superiorly the soft palate
-anteriorly extends for some distance under palatoglossal arch
-deep surface is covered by a capsule
Usually the tonsil and its capsule are separated easily from pharyngeal bed except for when __________ Why?
-after chronic tonsillitis, when there is fibrous adhesion between capsule and deep tonsillar bed
-resection of capsule in these cases is likely to cause much bleeding because many blood vessels run into posterior tonsillar capsule
Each palatine tonsil is separated from the palatine and tonsillar branches of the facial artery by the _________. Describe the internal carotid artery's position relative to the tonsil.
-superior constrictor muscle
-internal carotid artery lies posterolatral to tonsil
If going from palatine tonsil to internal carotid artery, what structures would you cross?
-middle constrictor and palatopharyngeal muscles
-facial artery and its tonsillar branch, ascending pharyngeal artery, glossopharyngeal nerve
Blood supply and venous drainage of palatine tonsils
-receives blood from facial artery through its ascending and tonsilar branches, the ascending pharyngeal artery of external carotid, and descending palatine branch of maxillary artery
-one or more veins leaves inferior part of tonsil and open into pharyngeal plexus or facial vein
What vessel courses close to lateral surface of palatine tonsil?
-large external palatine vein aka paratonsillar vein
-descends from palate and passes close to lateral surface of palatine tonsil before joining the pharyngeal plexus of veins
Describe where innervation of palatine tonsils comes from and why this can explain why tonsillitis may refer pain to ear?
-nerves to palatine tonsil are from the pterygopalatine ganglion through lesser palatine nerve and from the glossopharyneal nerve, which by its tympanic branch, also supplies mucosa of tympanic cavity; hence by tonsillitis can refer pain to ear
Describe lymphatic drainage of palatine tonsils and why nicknames have arisen
-to LN near angle of mandible and to jugulodigastric node
-due to frequent enlargement of jugulodigastric node in tonsillitis, often called tonsillar node
Where and when may a peritonsillar abscess develop? Why can this be troublesome?
-external to tonsillar capsule
-usually following bought of acute suppurative tonsillitis
-abscess may penetrate wall of pharynx and break through into retropharyngeal space and lead to spread of infection to mediastinum
What is the lymphatic ring of the throat and what is another name for it? What are its components?
-protective annulus of lymphoid tissue located in naso- and oro-pharynx
-lingual tonsil anteriorly and inferiorly, palatine and tubal tonsils laterally and pharyngeal tonsil superoposteriorly
Name the 4 arteries of the pharynx
-ascending palatine branch of facial artery
-descending palatine and pharyngeal branches of maxillary artery
Where do the veins of the pharynx drain and communicate with?
-drain into pharyngeal plexus of veins and thence into internal jugular vein
-pharyngeal plexus communicates with pterygoid venous plexus
Give parasympathetic, sensory, and motor nerve innervation of nasopharynx
-sensory supply of mucous membrane is mainly from pharyngeal branch of maxillary nerve V2
-motor nerve supply to muscles of palate is from pharyngeal plexus, except for tensor veli palatini which is innervated by CN V3
-parasympathetic secretomotor innervation to the mucous glands is derived from pterygopalatine ganglion
Where is the pharyngeal plexus of nerves found and what 3 components feed into it?
-on middle constrictor muscle
-formed by brances of vagus and glossopharyngeus nerves and sympathetic branches from superior cervical sympathetic ganglion
2 muscles not supplied by vagus n
-tensor veli palatini (CN V3)
-stylopharyngeus (CN IX)
Sensory fibers in the pharyngeal plexus are derived mainly from glossopharyngeal nerve and innervate most of the mucosa of the pharynx except for the nasopharynx which is innervated mainly by _______.
-pharyngeal branch of CN V2
4 types of fibers found in vagus nerve
-skeletal motor axons, preganglionic parasympathetic axons, taste fibers, and general sensory fibers
The vagus nerve traverse the _________ and innervates all of the muscles of the palate except for _________, all of the pharynx except for ________ and all of the muscles of the _______.
-tensor veli palatini
The vagus nerve innervates mucosa where? What visceral sensations does it carry? And where does it convey preganglionic parasympathetic axons?
-root of tongue and in laryngopharynx and larynx
-visceral sensation other than pain from thoracic and abdominal viscera
-preganglionic parasympathetic axons to terminal ganglia in thoracic and abdominal viscera
Complete lesions of vagus nerve commonly result in a weakness of __________, _________, and _________ muscles.
Weakness of levator veli palatini due to vagus lesion may result in what?
-drooping of palate on side of injured nerve
-deviation of uvula to side of uninjured nerve
-patients may have nasal speech and nasal regurgitation of liquids during swallowing
Weakness of pharyngeal constrictors due to vagus lesion may result in...
-dysphagia or difficulty swallowing
Lesions of vagus that include laryngeal nerves may result in a weakness of all laryngeal muscles on the affected side. What position will vocal cord be in and what does this result in?
-vocal cord will assume a fixed position midway between abduction and adduction, resulting in weak, hoarse speech
What reflex-ually happens if pharyngeal branches and laryngeal nerves are lesioned (of vagus)?
-loss of motor limb of gag reflex and cough reflex, respectively
Name the adductors, abductors, tensors, and relaxers of the vocal cords
-adductors: arytenoid muscles and lateral cricoarytenoid muscles
-abductors: posterior cricoarytenoid muscles
-tensors: cricothyroid muscles
-relaxer: thyroarytenoid muscles
The recurrent laryngeal nerve innervates all the intrinsic muscles of the larynx except for which one and what is it innervated by?
-cricothyroid: external branch of superior laryngeal nerve