Larynx Flashcards
Functions of the larynx
-maintains a patient airway
-protects the lower respiratory tract
-phonation
What does the larynx consist of
-cartilaginous skeleton
-membranes
-muscles
One bone 9 cartilages
Thyroid cartilage (adams apple)
-located at the level of the 4th vertebrae
-laminae x2
-superior horns x2
-inferior horns x2
-thyroid notch
Cricoid cartilage
-located at the level of the 6th cervical vertebrae
-forms a complete ring
-arch (anterior)
-lamina (posterior)
-articular facets
Epiglottis
-leaf shaped
-attached to posterior aspect of the anterior angle of the thyroid cartilage
-extends upwards and backwards behind tongue
-covers the laryngeal inlet during swallowing
Arytenoid cartilages
-pryamidal in shape- apex, base, 3 surfaces
-muscular process- where muscles attach
-vocal process- where vocal cords attach
-rotates around vertical axis and slides on the slope of the cricoid lamina
Membranes
-the laryngeal skeleton is lined by three membranes
-thyroid, quadrangular, cricovocal
Thyroid membrane
-extends from thyroid cartilage to hyoid bone
-thickened to form medial and lateral thyrohyoid ligaments
Quadrangular membrane
-extend from body and apex of arytenoids to lateral edge of epiglottis
-the free upper border forms the aryepiglottic fold- one on either side forming the boundary of the laryngeal inlet
-the free lower border forms the vestibular fold (false vocal cord)
Cricovocal membrane
-attaches inferiorly to cricoid cartilage
-attaches superiorly to thyroid angle and to the vocal processes of the arytenoids
-the free upper border forms the vocal fold (true vocal cord)
Regions of the larynx
-laryngeal inlet:opening into larynx
-glottis:space between the tow vocal cords
-supraglottic cavity (vestibule) : between inlet and vestibular folds
-laryngeal ventricles (sinuses): between vestibular and vocal folds. Saccule extends laterally
-infraglottic cavity: between vocal folds and inferior border of cricoid cartilage
Mucosa (lining/ covering) of the larynx
-superglottic and infraglottic cavities- respiratory epithelium, seromucous glands
-vestibular folds- respiratory epithelium, mucous glands
-ventricle- respiratory epithelium, saccule contains mucous glands
-vocal folds- stratified squamous epithelium in areas of contact-no mucous glands
What are the extrinsic muscles of the larynx
- move the whole larynx
-longitudinal pharyngeal muscles
Extrinsic- infrahyoid muscles
-the infrahyoid muscles originate below and insert onto the hyoid bone
-they depress and fix the hyoid bone and larynx
-superior belly omohyoid, inferior belly of omohyoid (omo=shoulder), thryohyoid, sternothyroid, sternohyoid
Extrinsic- suprahyoid muscles
-originate above and insert onto the hyoid bone
-if the mandible is fixed they elevate the hyoid bone and larynx
-if the hyoid bone is fixed they depress the mandible
-mylohyoid, geniohyoid, anterior belly of digrastic, posterior belly of diagrastic