Week 2 Flashcards
What are the functions of larynx
Airway protection
Phonation
Laryngeal skeleton
9 cartilages:
3 single (thyroid (hyaline), cricoid(hyaline), epiglottis(elastic))
3 paired (arytenoid, corniculate and cuneiform)
Attachments of the larynx
Thyrohyoid membrane- thyroid cartilage to hyoid bone
Cricotracheal ligament- cricoid cartilage to superior border of 1st tracheal cartilage
Function of epiglottis
Mobile part of the larynx
When swallow epiglottis moves and covers airways, diverts food into oesophagus
Vocal ligaments
Run from vocal process of arytenoid cartilage to thyroid cartilage
Free thickened edge of conus elasticus
Vestibular ligaments
Free thickened edge of quadrangular membrane attached to arytenoid cartilage and thyroid cartilage
Quadrangular membrane runs from edge of epiglottis inferiorly down larynx
‘False vocal fold’
Ventricle in larynx
Between vestibular fold and vocal fold
Vestibule larynx
Above vestibular folds
Infraglottic space
Beneath vocal folds
Rima glottidis
Space between vocal ligaments
Phonation
Vocal folds adducted and stridulating as air is forced between them
Vestibule open
Vibration of air causes sound
Intrinsic muscles of larynx
Cricothyroid
Oblique and transverse arytenoid
Posterior crico-arytenoid
Lateral crico-arytenoid
Thyro-arytenoid
Posterior crico-arytenoid function
Abduct vocal folds
Lateral cricoarytenoid function
Adduct vocal folds
Transverse arytenoid function
Adduction vocal folds
Oblique arytenoid function
Adduction vocal folds
Thyroarytenoid function
Shorten vocal ligaments
Cricothyroid function
Lengthen vocal ligaments
Cricothyroid muscle
Straight part and oblique part
Only laryngeal muscle innervated by external branch of superior laryngeal nerve (from vagus nerve)
Pulls thyroid cartilage anteriorly
Increases pitch
Lengthening and tightening vocal ligaments posteriorly
What are the intrinsic laryngeal muscles except Cricothyroid innervated by
Recurrent laryngeal nerve/ inferior laryngeal nerve
Internal branch of superior laryngeal nerve
Sensory innervation of mucous membrane superior to and including vocal fold
Pierces thyrohyoid membrane
Recurrent laryngeal nerves
The right recurrent laryngeal nerve loops under the right subclavian artery
The left recurrent laryngeal nerve loops under arch of the aorta
Sensory innervation of mucosa of infraglottic cavity- beneath vocal fold
Posterior crico-arytenoid muscle
Increased abduction during increased respiration
Only muscle to abduct the vocal folds
Larger space for air to pass down into airways
Inserts into muscular process of arytenoid cartilage
Arterial Blood supply of larynx
Superior laryngeal artery pierces thyrohyoid membrane. Branch of superior thyroid artery which is a branch of external carotid artery which is a branch of the common carotid
Common carotid bifurcates at level of superior border of thyroid cartilage
Inferior laryngeal artery- inferior thyroid artery- thryocervical trunk comes from subclavian artery
Venous drainage of larynx
Right and left
Internal jugular veins :
Superior thyroid vein -Superior laryngeal vein
Middle thyroid vein
Left brachiocephalic vein: inferior thyroid vein- inferior laryngeal vein
Autonomic nervous system
Parasympathetic- bronchoconstriction
Sympathetic- bronchodilation
Phrenic nerve
Pericardial branch- sensory innervation to pericardium
Motor innervation to diaphragm
