The larynx (voice box) is a component of the respiratory tract that is located in the anterior neck and is of great importance to many functions, including phonation, the cough reflex, and protection of the lower respiratory tract. Structurally, the larynx is secured together by ligaments and membranes and hosts the laryngeal muscles that move components of the larynx for phonation and breathing.
The larynx spans the cervical vertebrae C3 and C6, and is suspended from the hyoid bone. It is covered anteriorly by the infrahyoid muscles and laterally by the lobes of the thyroid gland. Posterior to the larynx is the oesophagus, a notable structure during emergency intubation, when pressure can be applied to the cricoid cartilage of the larynx to occlude the oesophagus, preventing regurgitation of gastric contents (Sellick’s manoeuvre).
The internal cavity of the larynx is divided into three sections: supraglottis (from the inferior surface of the epiglottis to the vestibular folds), glottis (containing vocal cords and 1 cm below them), and subglottis (from inferior border of the glottis to the inferior border of the cricoid cartilage). The interior surface of the larynx is lined by pseudostratified ciliated columnar epithelium, except for the true vocal cords, which are lined by a stratified squamous epithelium.
The arterial supply to the larynx is through the superior and inferior laryngeal arteries, while the venous drainage is carried out by the superior and inferior laryngeal veins. The superior laryngeal vein drains to the internal jugular vein via the superior thyroid, and the inferior laryngeal vein drains to the left brachiocephalic vein via the inferior thyroid vein.
The larynx is innervated both motor and sensory innervation through branches of the vagus nerve. The recurrent laryngeal nerve provides sensory innervation to the infraglottis, and motor innervation to all the internal muscles of larynx (except the cricothyroid). Meanwhile, the superior laryngeal nerve's internal branch provides sensory innervation to the supraglottis, and the external branch provides motor innervation to the cricothyroid muscle.
The vocal cords, as part of the larynx, are responsible for the production of speech, making them of utmost clinical relevance. Vocal cord paralysis is an important condition in which the vocal cords fail to open and close properly, and can lead to a variety of symptoms, including breathy or hoarse-sounding speech, difficulty with swallowing, and even wheezing. The treatment for vocal cord paralysis can vary, and is dependent on the cause of the paralysis and the severity of symptoms. Treatment options include speech therapy, surgery, or voice rest.
Overall, understanding the anatomy of the larynx and its relation to other structures in the neck is a vitally important component of clinical practice. Knowing the structure and anatomy of the larynx can assist clinicians in diagnosing and effectively treating a variety of conditions.
The larynx is supplied by the superior and inferior laryngeal arteries, which are branches of the external carotid and the thyrocervical trunk, respectively. The superior laryngeal artery follows the internal branch of the superior laryngeal nerve into the larynx, while the inferior laryngeal artery follows the recurrent laryngeal nerve into the larynx. Venous drainage of the larynx is accomplished by the superior and inferior laryngeal veins.
The larynx is a complex and essential structure in the upper neck, located between the pharynx and trachea. It is made up of cartilaginous skeleton, ligaments, membranes, and intrinsic muscles, and plays an essential role in phonation, protection of lower airways, and coughing reflex. Its primary supply of nourishment comes from multiple branches of the thyroid and brachiocephalic vasculature, and motor and sensory innervation is supplied by the recurrent and superior laryngeal nerves of the vagus nerve.
Damage to the recurrent laryngeal nerve is a notably important clinical concern, due to the potential for vocal cord paralysis causing hoarseness and, in some cases, a need for immediate intubation.
The larynx is an essential part of the human body, and its primary functions include phonation (voice production), protection of lower airways, and coughing reflex. Voice production occurs through the vibration of the vocal cords, which are situated within the larynx. Through the vibration of these cords, sound is produced from the airstream, which is essential for communication.
The larynx is also important for protecting the lower airways, as it serves to protect the trachea from food aspiration. In the event that food or other substances enter the larynx, coughing reflex is triggered to expel the object.
Damage to the recurrent laryngeal nerve is a noteworthy clinical complication, as it can lead to vocal cord paralysis. Vocal cord paralysis can manifest itself as changes in voice pitch and volume, hoarseness, and difficulty with speech and swallowing. In some cases, vocal cord paralysis can be so severe that emergency intubation is required.
Vocal cord paralysis can be caused by a variety of conditions, including neck and chest injuries, tumors of the neck and chest, certain neurological and muscular diseases, and infections. Fortunately, vocal cord paralysis can be managed medically or surgically, depending on the cause.
The larynx is a complex structure of cartilage, ligaments, membranes, and intrinsic muscles that is essential for phonation, protection of lower airways, and coughing reflex. It is nourished by multiple branches of the thyroid and brachiocephalic vasculature, and is supplied motor and sensory innervation from the recurrent and superior laryngeal nerves. Damage to the recurrent laryngeal nerve can cause vocal cord paralysis, and is potentially life-threatening in some cases. Fortunately, vocal cord paralysis can be managed medically or surgically, depending on the cause.
