Larynx

The larynx - in medical jargon larynx [ la ː rʏŋks ] ( from Ancient Greek λάρυγξ larynx, throat ') - formed as part of the respiratory tract, the transition from the pharynx to the trachea in the anterior neck region. From the outside, the people in the middle of the neck to the Adam's apple, which corresponds to the central projection of the thyroid cartilage. Embryo arises from the fourth to sixth branchial arch. The diseases of the larynx are the subject of laryngology, a branch of Oto- Rhino-Laryngology.

The larynx has two functions. Firstly, it protects the trachea before dining pieces, pulled forward by swallowing the larynx above and is thus closed by the epiglottis. Second, the vocal folds in mammals regulate the flow of breathing air and produce the sounds and vibrations of the human voice. Although birds also possess a larynx, but without the vocal folds and epiglottis. For phonation in birds is the syrinx, also referred to as "lower larynx ", in charge.

Construction

The larynx consists of three major cartilage, the thyroid cartilage ( cartilage thyroid ), the cricoid cartilage ( cricoid cartilage ), and the epiglottis ( epiglottis ), the two smaller arytenoid cartilages ( cartilages arytaenoideae ) as well as their accompanying Squirrel cartilages ( cartilages corniculatae ). The thyroid cartilage forms the anterior wall of the larynx and can be seen especially at the upper edge of the outside and palpable. Below is the horizontal cricoid cartilage, followed by the cartilages ( cartilages tracheal ) of the trachea. The arytenoid cartilages ( arytenoid ) sit behind the cricoid cartilage on an articulated manner. The epiglottis is connected to the thyroid cartilage and closes the laryngeal inlet to the throat.

The cartilages are held together by different bands, and the larynx is suspended from above by a membrane at the hyoid bone ( hyoid ). The vocal folds or vocal cords ( ligaments vocalia ) are stretched between the arytenoid cartilages and the posterior wall of the thyroid cartilage. They are of special muscles ( muscles of the larynx → ) moves. Inside is lined with a mucous membrane of the throat.

Through the regulation of length and tension of the vocal folds, through which it along by pulling vocal muscle fibers and especially by the laryngeal muscles of the basic sound of voice or singing is formed. This primary laryngeal sound ( primary sound ) is formed by movements of the tongue and mouth to speech sounds. Your full sound given the vote by the resonances in the throat, mouth, and nasal cavity (→ vocal tract ).

Topography

Above the larynx is the throat ( pharynx ), enters both the air from the mouth and nose as well as the food in the. Down the larynx continues into the trachea. The beginning of the esophagus lies behind, in animals over the larynx. Both are located in an area of loose connective tissue, which is limited by the front middle and rear of the rear journal of the cervical fascia. The middle sheet is stretched between the two Musculi omohyoidei (shoulder blade - hyoid muscles) from the rear surrounds the cervical spine with their muscles. Below the larynx is the thyroid. Side of the larynx and the esophagus is located in the same room the neurovascular road of the collar.

Function

The larynx plays an essential role in human voice production ( phonation ) or phonation in the other mammals. The muscle cricoarytenoid posterior ( also " posticus " in animals muscle cricoarytenoid dorsalis) rises behind the cricoid cartilage and puts the back of the processus muscularis (muscle protrusion ) of the arytenoid cartilage of the respective side, pulls him inside and thus the vocal folds, the joint front against the are connected to the arytenoid cartilages, apart.

This Stimmritzenöffner face three make the glottis ( glottis ). The muscle cricoarytenoid lateralis arises from the front outside of the cricoid cartilage, also relies on the muscular process and thus makes exactly the opposite movement as the posticus. The transverse and oblique arytenoid cartilage muscle ( mm. arytenoidei oblique and transversus ) directly connect the two arytenoid cartilage and pull them together. For the formation of the voice of the vocal cord muscle (musculus vocalis ) is important to the thyroarytaenoideus the outside of the vocal folds is present as part of the muscle and its voltage regulated.

The frequency with which vibrate the vocal cords, the pitch, the amount of air flow on the other hand determines the volume. In addition to the resonances in the throat, mouth, and nasal cavity occurs through resonance and vibrations in the chest and sinuses. In breast resonances the voice is worn and slightly darker than head resonance. Permanent hoarseness with no apparent organic cause is often due to the fact that the resonant cavities are little used and therefore the voice is overtaxed.

When swallowing, the larynx is pulled both the hyoid bone and against the hyoid bone upward and thus pressed the epiglottis against the fat pad of the cervical wall. By the contraction of the tongue, which forms the front wall of the neck, the epiglottis closes the larynx complete. When trying to talk at the same time while eating, it may happen that small amounts of food or liquid contact with the mucous membrane of the larynx and trachea, resulting in a strong cough.

Nerve and vascular supply

The superior laryngeal nerve (upper laryngeal nerve, called with animals cranial laryngeal nerve ) supplies motor the external laryngeal muscles ( cricothyroid ) and sensitively the larynx above the glottis. He comes from the vagus nerve ( tenth cranial nerve).

The inferior laryngeal nerve (lower laryngeal nerve, called with animals caudal laryngeal nerve ) supplies motor the inner muscles of the larynx and the sensitive mucous membrane of the larynx below the glottis. He also comes from the tenth cranial nerve.

The superior laryngeal artery (upper laryngeal artery) that supplies the larynx above the glottis, is a branch of the superior thyroid artery. They achieved their goal through a perforation in the membrane ( thyrohyoid membrane ), at which the larynx is suspended from the hyoid bone. The inferior laryngeal artery (lower laryngeal artery) originates from the thyrocervical trunk ( inferior thyroid artery ) of the subclavian artery ( subclavian artery ). It supplies ascending the trachea and the lower part of the larynx.

The course of the vein is based on the of the arteries, as in most regions of the body.

Diseases

Malformations (shape ) abnormalities of the larynx are relatively rare.

An inflammation of the larynx is called laryngitis. It can occur for example in an infection of the respiratory tract. Certain infectious diseases manifest themselves preferred as laryngitis, such as diphtheria ( " Krupp "). As Pseudokrupp the subglottica laryngitis, an inflammation of the larynx is called just below the vocal cords. The larynx cancer is generally a disease of smokers.

An aneurysm of the laryngeal ventricle is called laryngocele.

A flaccid paralysis of the glottis with Intermediärstellung of one or both vocal cords as a result of damage to the inferior laryngeal nerve ( recurrent laryngeal nerve ) and the superior laryngeal nerve is called a cadaver position. In horses, a unilateral paralysis of the recurrent laryngeal nerve occurs on quite often and leading to unilateral vocal cord paralysis ( laryngeal whistling, roaring English ). The Recurrenslähmung and subsequent breathing problems can perhaps be addressed in future with a laryngeal pacemaker. In Innsbruck, Gera and Würzburg, this device has been successfully used in patients. Thus, the air supply could be improved without the voice and influence to speak negatively.

When Injuries to the superior laryngeal nerve may, among come to restricted movement of the musculus cricothyroideus. Since this is responsible for the coarse voltage of the vocal cords and the associated regulation of tone of voice, it can come in restrictions on so-called " robot " phenomenon. The patient loses the ability to regulate the tone of voice when speaking to change the pitch. In addition, the voice sounds hoarse and weak.

Investigation

1858, the laryngoscopy was introduced as a mirror viewing with reflected light from the outside, so using a laryngeal mirror and a front mirror, in clinical practice by Ludwig Türck and Johann Nepomuk Czermak. For examination of the larynx cold light source or LED lighting, especially endoscopes are now usually worn next to the examination by laryngeal mirror under illumination with a on the forehead used. The laryngeal endoscope, a rigid endoscope that is inserted into the mouth and allows a 90 ° - or occasionally 70 ° optics to look down into the larynx, on the other hand, a flexible endoscope, which is inserted through the nose and throat and to in this way allows the examination of the larynx.

From the outside, one can examine the larynx groping or use a CT scan or magnetic resonance imaging investigation.