Larynx and Trachea Flashcards
Relationships around Larynx?
Hyoid superiorly
Inferior pharyngeal constrictor muscle (cricopharyngeus + thyropharyngeus) posteriorly
Trachea inferiorly
Strap muscles of the neck anteriorly
Thyroid Angle of men and women?
Thyroid angle male (90°) vs. female (120°)
Arytenoid Cartilages Role?
2 pyramid-shaped small cartilages that articulate with the cricoid cartilage
Apex: articular facets for corniculate cartilages
Vocal Process: attachment for vocal cords (Elastic cartilage at tips)
Muscular Process: attachment for posterior & lateral cricoarytenoid muscles
Role of Corciculate Cartiledges?
Small horn-like cartilages (elastic)
Serve to extend arytenoid cartilages medially & posteriorly
Sometimes fused with arytenoid cartilage
THE QUADRANGULAR MEMBRANE IS SUPERIOR TO THE VOCAL LIGAMENT/FOLD
THE CONUS ELASTICUS IS INFERIOR TO THE VOCAL LIGAMENT/FOLD
ONLY MUSCLE TO TENSION VOCAL CHORDS?
Cricothyroid Muscle
Innervation: External branch of superior laryngeal nerve (CNX)
Innervation of Muscles Controlling Vocal Folds?
ALL Intrinsic muscles of the larynx receive recurrent laryngeal nerve
Cricothryroid is innervated by the Superior Laryngeal nerve
Where does the Superior Laryngeal Nerve arrise and what does it innervate?
Arises from inferior vagal ganglion in carotid triangle
Internal Branch: pierces thyrohyoid membrane with superior laryngeal artery. Supplies sensory fibers to the laryngeal mucosa of the laryngeal vestibule and middle laryngeal cavity (including the superior surface of the vocal folds)
External Branch descends posterior to the sternothyroid muscle with the superior thyroid artery. Initially the external branch lies on the inferior pharyngeal constrictor muscle (contributing to its innervation) before piercing and passing through it and continuing to supply the cricothyroid muscle
Where does the Inferior Laryngeal Nerve arise and what does it innervate?
Inferior Laryngeal Nerve is the continuation of the recurrent laryngeal nerve. It enters the larynx by passing deep to the inferior border of the inferior pharyngeal constrictor and medial to the lamina of the thyroid cartilage. It divides into anterior and posterior branches which accompany the inferior laryngeal artery into the larynx
Anterior Branch supplies lateral cricoarytenoid, thyroarytenoid, vocalis, aryepiglottic and thyroepiglottic muscles
Posterior Branch supplies posterior cricoarytenoid, interarytenoid (transverse & oblique) muscles
Vagal Nerve Asymmetry?
Left RLN loops around the arch of aorta
Right RLN loops around the subclavian artery
Lymphatics of Larynx
Above the vocal folds, lymphatics accompany superior laryngeal artery, through thyrohyoid membrane to superior deep cervical nodes
Below vocal folds, lymphatics drain to the pretracheal or paratracheal nodes and subsequently to the inferior deep cervical nodes
Trachea contains _____ C-shaped hyaline cartilaginous rings that maintain patency of airway. Posteriorly enclosed by _______ muscle.
Trachea contains ~16 C-shaped hyaline cartilaginous rings that maintain patency of airway. Posteriorly enclosed by trachealis muscle.
Where is the incision made for an Emergency Cricothyroidotomy?
Incision made through median cricothyroid ligament to bypass the obstruction.
