Lecture 19 - Pharynx and Larynx Flashcards
Pharynx
Extends between rami of the mandible and the base of the cranium Divisions: nasopharynx, oropharynx, hypopharynx •Muscles of mastication pass on either side of the pharynx in the infratemporal fossa from cranium to mandible. •Posteriorly the pharynx is in contact with the prevertebral fascia of the somatic neck.
Nasopharynx
Opens into nasal cavity
Oropharynx
Opens into oral cavity
Hypopharynx
Continuation into larynx and esophagus •Nasal choanae mark beginning of nasal pharynx. •Floor is formed by soft palate. •Posteriorly and superiorly relations are the atlas and the basilar occipital bone. •Auditory tube opens on lateral wall of nasopharynx. •Cartilaginous wall of the tube creates the torus tubarius.
Salpingopharyngeus muscle
Nasopharynx •Originates from end of auditory tube •Raises pharynx during swallowing •Covered by salpingopharyngeal fold
Pharyngeal tonsils
Nasopharynx •AKA: adenoids •Embedded in posterior wall of nasopharynx •Regress by 8 years
Faucial pillars
Oropharynx •Palatoglossus muscle •Palatopharyngeus muscle
Tonsillar fossae
Oropharynx •Lie between diverging fauces •Contain palatine tonsils •Related to space between superior and middle pharyngeal constrictors •Represents the second pharyngeal pouch
Tonsils
Arterial supply: •Tonsilar branches from: •Maxillary artery (branches of) •Facial artery (branches of) •Lingual artery (branches of) Waldeyer’s ring: •Ring of lymphoid tissue around pharynx; includes: •Pharyngeal tonsils •Palatine tonsils •Tubal tonsils •Lingual tonsils
Pharyngeal Musculature
three overlapping constrictors and three diagonal muscles: •Meet posteriorly at pharyngeal raphe. •Overlap constrictor muscles above. •Lateral gaps occur between constrictor muscles anteriorly. •Used in swallowing
Superior constrictor (pharyngeal)
•Lies deep to mandibular ramus in infratemporal fossa •Attached to pterygoid plate and mandibular and maxillary alveolar processes •Posteriorly attached to pharyngeal tubercle of occipital bone •Superior edge is free, creating a narrow space below the base of the cranium: •Provides passage for auditory tube
Middle constrictor
•Arises anteriorly from stylohyoid ligament and horns of hyoid bone •Fibers pass posteriorly to pharyngeal raphe •Separated from superior constrictor by a gap: •Provides passage for stylopharyngeus muscle, pharyngeal branch of CN IX, and tonsillar branch of facial artery
Inferior constrictor
•Fans out superiorly but becomes more tubular inferiorly •Fibers insert posteriorly on pharyngeal raphe •Cricopharyngeus portion of muscle functions as a sphincter at superior end of esophagus
Gap above superior pharyngeal constrictor
•Closed by pharyngobasilar fascia •Traversed by auditory tube •Forms tonsillar bed
Gap above middle constrictor
Traversed by: •Stylopharyngeus muscle •Glossopharyngeal nerve
Palatopharyngeus muscle:
•Underlies posterior faucial pillar (palatopharyngeal fold) •Arises from palate and inserts on pharyngeal musculature •Functions as sphincter between oral cavity and pharynx •Helps raise larynx during swallowing •Innervated by CN X
Salpingopharyngeus muscle:
•Lies under salpingopharyngeus fold •Originates from torus tubarius •Inserts onto midpharynx musculature •Raises pharynx and larynx during swallowing •Innervated by CN X
Stylopharyngeus muscle:
•Originates from styloid process •Passes through hiatus between superior and middle constrictors •Inserts onto pharyngeal musculature and thyroid cartilage •Raises pharynx during swallowing •Innervated by CN IX
Glossopharyngeal nerve (IX):
•Nerve of third arch •Exits skull via jugular foramen •Winds around stylopharyngeus muscle and enters pharynx through gap between superior and middle pharyngeal constrictors •Supplies stylopharyngeus muscle
Vagus nerve (X):
•Nerve of fourth (through sixth) arch •Supplies all pharyngeal musculature except stylopharyngeus muscle
Innervation and Blood Supply of Pharynx
Innervation: •Vagus nerve via pharyngeal plexus: •Except stylopharyngeus (CN IX) •Recurrent laryngeal nerves branches of vagus nerve) to lower part of inferior constrictor Blood supply: •Ascending pharyngeal artery
Larynx
formed by a rigid framework of bones, cartilage, and ligaments: Unpaired symmetrical structures: •Hyoid bone •Thyroid cartilage •Cricoid cartilage •Epiglottis •Paired cartilages: •Arytenoid •Corniculate •Cuneiform Function: •Compound sphinctor: •Closes airway during swallowing and Valsalva’s maneuver •Constricts airway for phonation
Hyoid
“U”-shaped bone: •Median body •Greater cornua(horns) •Superior cornua Attachment site for numerous muscles
Epiglottis
Spoon-shaped structure that extends posteriorly and superiorly into the hypopharynx. attached to hyoid and thyroid cartilage. 2 folds and vallecular recesses Anterior surface is attached to the hyoid: •Hyoepiglottic ligament Attached to the thyroid cartilage: •Thyroepiglotticligament
Piriform Recess
Part of laryngopharynx lateral to larynx. Lateral boundary: •Thyrohyoid membrane and thyroid cartilage Medial boundary: Aryepiglottic fold; arytenoid and cricoid cartilages. •Site of lodgement
Laryngeal Cavity and Folds
Characterized by superior and inferior pairs of folds
Vestibule
lies between vestibular folds
vestibular folds
false vocal cords rima vestibuli (space btwn vestibular folds)
Ventricular folds
true vocal cords vocal ligaments
rima glottidis
space btwn vocal folds narrowest part of laryngeal cavity opens and closes to regulate the passage of air
infraglottic cavity
lies btwn ventricular folds and lower border of cricoid cartilage continuos inferiorly with trachea
Superior laryngeal artery:
From superior thyroid artery
Inferior laryngeal artery:
Branch of inferior thyroid artery
Piriform fossae
Inferior to lateral glossoepiglottic folds
Innervation of the epiglottis
Glossopharyngeal nerve: •Sensation from upper epiglottic surface Superior laryngeal nerve (CN X): •Taste buds of epiglottis •Sensation from lower epiglottis surface and supraglottic larynx (cough reflex)
Folds of the epiglottis
•Median glossoepiglottic fold •Paired lateral glossoepiglottic folds
Vallecular recesses (epiglottis)
•Located on either side of the median glossoepiglottic fold •Common sites for lodgement
Thyroid
Arytenoids
