Definition and anatomical location
The larynx is a section of the airways that contains the vocal apparatus and connects the pharynx to the trachea. The larynx is connected by ligaments to the hyoid bone and is on the same level as the 4, 5, and 6 cervical vertebrae on the front of the neck. It is a hollow organ formed from a ligamentous apparatus, cartilage skeleton and muscles. The structure of the larynx allows you to feel its individual parts, such as the male Adam's apple and the female cricoid cartilage. In its upper part there is an entrance in the form of an opening, here the larynx connects to the pharynx, and in the lower part it passes into the trachea. Near the larynx are the neurovascular cervical bundles, and on the sides of it is the thyroid gland. In the human body, this organ is of great importance, because thanks to the larynx, voice formation occurs. And it is also a transportation hub for air to enter the lungs.
Cartilage skeleton
The structure of the larynx includes cartilage of various structure and shape. The cartilaginous skeleton, which is its skeleton, consists of several movable cartilages, which are combined among themselves by movable joints, membranes and ligaments. The structure of the larynx includes paired (small) and unpaired (large) cartilage.
The largest unpaired cartilage is called thyroid. It contains two quadrangular plates connected to each other at an angle that is 45 ° for men and 120 ° for women. Two pairs of upper and lower horns branch off from the backs of these plates. The main part of the larynx is the cricoid cartilage, facing forward by an arc, and back by a plate. The lower portion of this cartilage combines the cricotracheal ligament with the first ring of the trachea. With two pairs of joints, the cricoid cartilage is combined with the arytenoid and thyroid cartilages.
The further structure of the human larynx is continued by the carob-shaped cartilage. It has small dimensions and is located at the apex of the arytenoid cartilage. The elongated wedge-shaped cartilage does not have a constant shape and size, often it is in a rudimentary state. The larynx is covered from above by the epiglottis, and it, in turn, is connected with the hyoid-epiglottis and shield-nasal ligaments, as well as with the thyroid cartilage.
Laryngeal joints and sound reproduction
Hyaline cricoid cartilage is considered the basis of the larynx. The ligaments and two joints are responsible for the mobility of the laryngeal cartilage:
1. The cricothyroid joint is paired, it consists of articular surfaces on the front side of the cricoid cartilage and the lower part of the thyroid cartilage. The movement of this joint occurs along the frontal axis, at which time with contraction of the muscles the thyroid cartilage bends forward and returns.
2. The cricoid joint is paired, it consists of articular surfaces based on the plate of the cricoid cartilage and on the basis of the arytenoid cartilage. In this joint, the movement occurs along the vertical axis, the vocal processes while together with the vocal cords alternately diverge to the sides and come together, due to which there is an expansion and narrowing of the vocal opening of the passage.
Voice unit
The structure of the larynx and pharynx is arranged so that inside them is the vocal apparatus, a very important instrument for humans. The vocal cords are attached to the arytenoid and thyroid cartilages. During contraction of the laryngeal muscles, the shape of the glottis and the degree of ligament tension change. During inspiration, the vocal cords vibrate , thus forming vowels. Consonants are produced with the participation of the lips, tongue and palate, but the larynx can also take part in the formation of “swallowing” consonants. Most of the sounds, unlike primates, a person pronounces on exhalation.