Cricoid cartilage. The anatomical structure of the larynx What cartilages are part of the human larynx

The larynx is the upper part of the respiratory tube, which is located in front of the neck at the level of 4-7 vertebrae. The larynx is connected to the hyoid bone by the thyroid-hyoid membrane and laterally adjacent to the thyroid-hyoid gland.

General characteristics of the larynx

The larynx plays an important role in the formation of human sounds and speech. Air entering through the larynx causes the vocal cords to vibrate and produces sounds. The circulating air flow in the mouth, pharynx and larynx is regulated by the nervous system and allows a person to speak and sing.

The larynx functions as a movement apparatus, which has cartilages connected to the ligaments and joints of the muscles, allowing the vocal cords to be regulated and the glottis to change.

The structure of the larynx is a skeleton of unpaired and paired cartilages.

Unpaired cartilages are

• thyroid cartilage, which consists of wide plates located at a certain angle;
• the cricoid cartilage is the basis of the larynx and is connected to the trachea with a ligament;
• the epiglottic cartilage closes the entrance to the larynx when eating and adheres to the surface of the thyroid cartilage with the help of a ligament.

Paired cartilages:

• the arytenoid cartilages are pyramid-shaped and connected to the plate of the cricoid cartilage;
• carob-shaped cartilages are cone-shaped and located in the aryepiglottic fold;
• the sphenoid cartilages are wedge-shaped and located above the corniculate cartilages.

The cartilages of the larynx are interconnected by joints and ligaments, and the free space is filled with membranes. When the air moves, the tension of the vocal cords occurs, and each of the cartilages plays a certain role in the formation of sounds.

The movement of all the cartilages of the larynx is regulated by the anterior muscles of the neck. These muscles change the position of the epiglottal cartilage during breathing, speech, singing, and swallowing.

The structure of the larynx is aimed at performing the speech function and ensuring the activity of the vocal apparatus.

• muscles of relaxation of the vocal cords - the vocal muscle, designed to narrow the glottis, and the thyroarytenoid muscle, located in the anterior lateral part of the thyroid cartilage;
• tension muscles of the vocal cords - cricothyroid muscle;
• glottis constriction muscles - the lateral cricoarytenoid muscle, which changes the position of the arytenoid cartilage, and the transverse arytenoid muscle, which brings the arytenoid cartilages together and stretches them;
• glottic expansion muscles - the posterior cricoarytenoid muscle, which rotates the arytenoid cartilage and changes the position of its vocal processes.

Diseases of the larynx

Diseases of the larynx are inflammatory, infectious and allergic.

The most common diseases of the larynx include the following.

Acute laryngitis, which is accompanied by inflammation of the mucous membrane of the larynx. This disease occurs as a result of exogenous and endogenous factors. Exogenous factors are irritation of the mucous membrane of the larynx, hypothermia, exposure to the mucous membrane of harmful substances (gas, chemicals, dust, etc.), the intake of very cold or very hot food and liquids. Endogenous factors include reduced immunity, severe diseases of the digestive system, allergies, atrophy of the mucous membrane of the larynx.

Laryngitis often manifests itself in adolescence, especially in boys with voice mutations. A serious reason for the development of acute laryngitis can be a bacterial flora - streptococcus, influenza virus, rhinovirus, coronovirus.

Infiltrative laryngitis is accompanied by inflammation of the mucous membrane of the larynx and deeper tissues. The inflammatory process takes place in the ligaments, perichondrium and muscles of the vocal apparatus. The main cause of infiltrative laryngitis are infections that penetrate the tissues of the larynx during infectious diseases and injuries.

Laryngeal angina is an acute type of infectious disease, which is accompanied by damage to the lymphatic tissues of the larynx, thickening of the mucous membrane and inflammation of the lingual surface of the epiglottis.

Laryngeal edema often develops with allergic reactions of various etiologies. Laryngeal edema manifests itself in the form of an inflammatory process of the mucous membrane and narrowing of the lumen of the larynx. This disease is the result of another inflammatory or infectious process in the larynx.

Acute swelling of the larynx can develop under the influence of inflammatory processes, acute infectious diseases, injuries and tumors, allergic reactions and pathological processes that take place in the larynx and trachea.

Stenosis of the larynx leads to a narrowing of the lumen and prevents air circulation in the low airways. With stenosis of the larynx, there is a high risk of asphyxia as a result of insufficient passage of air into the lungs.

Stenosis of the larynx of the larynx and tracheal type are considered and treated as a single disease. With a rapid course of the disease and a high risk of severe respiratory dysfunction, emergency medical attention is required.

Treatment of the larynx and restoration of the voice

The main factors for weakening ligaments and loss of voice are:

• viral infection;
• inflammation caused by tension of the ligaments and their overload;
• damage to ligaments in chemical or other production;
• loss of voice due to nervousness, due to neurosis;
• irritation of the ligaments with spicy foods, hot or cold drinks.

Treatment of the larynx is carried out, depending on the cause and type of disease. Usually the voice is restored without medical treatment, over time, the ligaments rest from tension and are restored.

There are several main ways to restore voice:

• elimination of an irritant or allergen (dust, smoke, spicy food, cold liquid, etc.);
• treatment of diseases of the pharynx - laryngitis, pharyngitis, tonsillitis;
• avoidance of tension in the ligaments, silence for several days;
• rest and warmth, compresses on the neck area.

If the inflammation of the ligamentous apparatus and larynx is chronic, then you should seek help from an otolaryngologist, undergo a medical treatment of the larynx and do special exercises to restore the voice and strengthen the ligaments.

The larynx is a hollow organ that is part of the respiratory tract and is involved in the act of breathing and voice formation. In an adult, the larynx is located on the anterior surface of the neck at the level of the fourth and sixth cervical vertebrae. In the upper section, it passes into the pharynx, in the lower section, into the trachea. Outside, this organ is covered with muscles and subcutaneous tissue and does not have a bone frame, so it is easy to feel through the skin. In addition, the larynx is easily displaced on palpation. This is due to the peculiarities of its structure and the ability to make active and passive movements.

The size of the larynx and the width of its lumen vary and depend on age, gender and individual characteristics of the organism.

• In men, the lumen of the larynx in the region of the vocal folds ranges from 15 to 25 mm.
• In women - from 13 to 18 mm.
• In children up to a year - about 7 mm.

It is with the relatively small lumen of the larynx in young children that the risk of development is associated.

The larynx has a rather complex structure. It consists of cartilage, which are interconnected with the help of ligaments, muscles and joints. This organ is closely connected with the nearby organs of the neck (pharynx, esophagus, thyroid gland), large vessels and nerves.

Cartilages of the larynx

The cartilaginous tissue that forms the larynx is represented by three large unpaired and three paired cartilages. The first group includes the cricoid, thyroid cartilage and epiglottis.

• The cricoid cartilage got its name from the external resemblance to the ring, it forms the basis of the skeleton of the larynx.
• The thyroid cartilage is the largest and protects the organ from external pressure. It is located above the cricoid and consists of two quadrangular plates fused together. These plates on the front surface at the place of their fusion form a bony protrusion called "Adam's apple", which is more pronounced in men.
• The epiglottis resembles a flower petal in shape; it is attached with a narrow stalk to the thyroid cartilage and prevents the penetration of saliva and food masses into the respiratory tract.

Paired cartilages of the larynx perform their functions:

• The sphenoid and corniculate cartilages are considered to be sesamoid and have variable shape and size. They strengthen the outer ring of the larynx and act as shock absorbers when closing the respiratory gap with the epiglottis.
• The arytenoid cartilages resemble trihedral pyramids in shape; muscle fibers are attached to them.

The joints of the larynx

The larynx is a fairly mobile organ, it shifts when talking, singing, swallowing and breathing. To carry out this helps her articular and muscular apparatus. There are two large paired joints of the larynx: cricoid and cricoid.

• The first of these allows the thyroid cartilage to tilt forward and back to its original position. This provides tension and relaxation of the vocal cords.
• The second joint allows the arytenoid cartilages to perform rotational, sliding movements, as well as to perform tilts, which ensures a change in the size of the glottis.

Muscles and ligaments of the larynx

The larynx has a developed muscular and ligamentous apparatus. All muscles of this organ can be divided into 2 groups:

• Internal (cause the movement of the cartilages of the larynx relative to each other, change the position of the epiglottis during swallowing and the tension of the vocal folds along with the size of the glottis): shield and aryepiglottic, transverse and oblique arytenoid, lateral and posterior cricoarytenoid, vocal, cricoid, thyroarytenoid.
• External (participate in the movement of the entire larynx as a whole and connect the surface of the thyroid cartilage with the hyoid bone and sternum): chin-, sternal-, scapular-, stylohyoid, digastric, thyroid-hyoid, sternothyroid.

Ligaments of the larynx connect it to the hyoid bone, trachea, root of the tongue, and also connect the cartilages to each other. Their presence ensures the correct position of the larynx and its mobility.

The internal structure of the body

Inside the larynx has a cavity narrowed in the middle section and expanded upward and downward. The entrance to it is limited by the epiglottis, arytenoid cartilages and aryepiglottic folds, on the sides of which are pear-shaped pockets. In the area of ​​these pockets, saliva can accumulate in case of obstruction of the esophagus or foreign bodies can be introduced.

On the inner surface of the larynx at the level of the lower and middle parts of the thyroid cartilage there are two pairs of mucosal folds - vocal and vestibular. Between them in the form of depressions there are laryngeal ventricles, in which there is an accumulation of lymphoid tissue - the laryngeal tonsil. With its inflammation, a person develops laryngeal tonsillitis.

From the point of view of clinical anatomy, the laryngeal cavity is usually divided into 3 floors:

• In the upper section, between the vestibular folds and the entrance to the larynx, its vestibule is located.
• The median space between the vocal folds is called the glottis.
• The area of ​​the larynx below the vocal folds and up to the trachea is the subvocal region.

The mucous membrane covering the larynx is a continuation of that of the pharyngeal cavity. All departments of the organ are lined with multinuclear ciliated epithelium, with the exception of the vocal folds and the epiglottis (there is a stratified squamous epithelium). Such a structure must be taken into account by the doctor in the diagnosis of the tumor process.

Another structural feature of the larynx wall is that in the region of the epiglottis, vestibule folds and subglottic space under the mucous membrane there is loose fiber, the presence of which causes rapid laryngeal edema in various pathological conditions.

Physiological significance

In a healthy person, the larynx performs the following functions:

1. Respiratory (conducts air into the lower parts of the respiratory tract and participates in the act of breathing, expanding or narrowing the glottis with the help of the neuromuscular apparatus).
2. Protective (the larynx has reflexogenic zones, irritation of which causes spasm of muscle fibers and closure of its lumen or reflex cough; isolates the airways from the esophagus; lymphoid tissue and ciliated epithelium of this organ prevents the penetration of microorganisms deep into the respiratory system).
3. Phonator (takes a direct part in the mechanics of the formation of sounds and the formation of speech).

Voice formation in the larynx occurs when an air flow passes through it due to the vibration of the vocal folds and the active work of the muscular apparatus. In addition to the larynx, the lungs, bronchi, trachea, and mouth are involved in this process. The coordinated activity of these structures is subject to the regulatory control of the cerebral cortex. In this case, the main sound is formed in the larynx, and the formation of speech is carried out through the articulatory apparatus (tongue, lips, soft palate).

Each person has his own timbre of voice, which is due to the individual anatomical features of his body. The pitch of the voice depends on the frequency of vibration of the vocal folds, their elasticity and size. The strength of the voice is determined by the power of the air flow that sets the vocal folds in motion, as well as their degree of tension. Thus, people with a low voice have relatively longer and wider vocal folds than those with a high voice.

Conclusion

The normal functioning of the larynx plays an important role in human life. Various changes in its structure and pathological processes lead to the inability of the larynx to perform its functions in full, which poses a threat to the health, and sometimes the life of the patient.

In the article we will talk about what laryngeal cartilages are, find out how they make up the skeleton of the larynx, their types, purpose and features of using this knowledge in medical practice. It is the cartilages of the larynx that provide the elevation on the front surface of the neck, clearly visible through the outer integument. The larynx itself with its powerful frame is located at the level of the penultimate three cervical vertebrae - IV, V, VI.

Attention! In all mammals, the cervical spine is formed by 7 vertebrae, and this is not affected by the length of the neck. Even the giraffe is no exception.

The larynx itself is part of the upper respiratory tract, which passes into the trachea at approximately the level of the VII cervical vertebra. It occupies the most anterior position in the neck in relation to its other visceral components.

Behind is the pharynx, which subsequently passes into the esophagus, and with which the larynx communicates near the oral cavity. Large vessels of the neck lie on the sides - the carotid arteries and jugular veins, the good patency of which is critical for the full functioning of the human body. More about this in the video.

The photo shows the topographic anatomy of the neck, the larynx itself and its relationship to other organs located in the neck.

A little about the physiological significance

The larynx, as an organ of the respiratory system, plays an important role in carrying air down to the underlying sections through the trachea and bronchi, up to the lung tissue, for gas exchange and oxygenation of the blood. In addition, the larynx is a sound-producing organ, which, like a complex musical instrument, under the influence of exhaled air, forms sound due to the vibration of stretched vocal cords.

Important! It was speech, which arises due to the work of the larynx, that was one of the most important factors in human evolution.

Cartilaginous framework of the larynx

Like every musical instrument, the larynx has its own structure, in which a skeleton formed by cartilage tissue is distinguished. Cartilages are connected to each other through ligaments, joints and muscles. The latter set the organ in motion, due to which the degree of tension of the vocal cords and the size of the glottis change.

The structure of the cartilage of the larynx is represented by two groups, the division of which was based on the pairing of these components:

1. Unpaired cartilages. Representatives of this group are the thyroid, cricoid and epiglottic cartilages.
2. Paired. The small number of cartilages included in the group does not in any way reduce their significance. The arytenoid cartilage belongs to the paired cartilages of the larynx.

More about each

Cricoid cartilage of the larynx

Its name is fully justified by its shape. It consists of a wide plate and a closed arc, which, like a ring, comes out from both sides of the plate.

Thyroid cartilage

It is the largest cartilage of the larynx, consisting of two large plates that fuse at an angle. Located between the hyoid bone and the cricoid cartilage.

Attention! A similar fusion of the plates of the thyroid cartilage forms an elevation, which is clearly visible to the naked eye. In the people it is customary to call it "Adam's apple" or "Adam's apple". At the same time, in women and children, these plates converge rounded, due to which they do not have such a protrusion.

The thyroid and cricoid cartilages are connected to each other by the cricothyroid ligament. It plays an important role in the treatment of emergency conditions, when it is necessary to quickly restore airway patency with your own hands not in an operating room.

Important! A conicotomy is an emergency procedure that is performed when tilting the head back and retracting the mandible does not work with an airway obstruction. Most often this occurs when the airways are blocked by a foreign body. The price of time is extremely high in such a situation.

epiglottal cartilage

It has the shape of a petal and differs from the above in the type of cartilage tissue, namely, it consists of elastic cartilage tissue, while others are made of hyaline. It is attached directly to the root of the tongue.

It closes the entrance to the larynx when eating, and, conversely, opens the entrance when talking. That is why talking while eating increases the risk of airway obstruction by a foreign body.

arytenoid cartilage of the larynx

It has the appearance of trihedral pyramids, which are directly related to the vocal cords, to which they are attached with their anterior process. Their second process is attached to the relaxer muscles, which play a role in the formation of the voice by changing the tension of the vocal cords.

Diseases accompanied by damage to the cartilage of the larynx

It:

• fracture of the cartilaginous larynx;
• inflammatory processes (epiglottitis in children);
• the spread of a malignant tumor of the larynx to the cartilage area (especially the epiglottis (see. ));
• dislocations and subluxations.

traumatic injury

The most common diseases of the laryngeal cartilage are traumatic effects on the skeleton of the larynx. Aggressive sports such as hockey, kickboxing and even baseball can be the cause. That is why athletes often use various protective devices to prevent, for example, a fracture of the cartilage of the larynx.

The thyroid and cricoid cartilages are most commonly affected. They lead to submucosal hemorrhages and edema, obstruction of the upper respiratory tract. Due to damage to the vocal cords or laryngeal nerve, significant hoarseness of the voice is also possible, up to a temporary loss of the ability to speak.

Dislocation of the laryngeal cartilage is also a traumatic condition, and can occur both in sports and in violent acts, such as strangulation. It can be either partial - with the defeat of only one joint, or complete.

Clinically, it will be manifested by cyanosis of the skin, an acute feeling of lack of air, dizziness. The intervention of a medical specialist is required.

In any traumatic condition, except for shortness of breath, the patient will be disturbed by pain when swallowing in the region of the laryngeal cartilages, but its severity is different with different intensity of the applied force.

Inflammatory processes in the cartilage of the larynx

While children under the influence of viral etiology can develop epiglottitis, adults can be affected by another ailment - chondroperichondritis. Very often it is a consequence of a previously inflicted injury in this area. It begins with an inflammatory process of the perichondrium, further affecting the cartilage itself.

Another inflammatory condition may be arthritis of the cartilage of the larynx. Often it has an autoimmune etiology and associated symptoms from other organs and tissues. The cricoarytenoid joint is most susceptible to this process.

In the first case, the thyroid cartilage of the larynx is more often affected, and, accordingly, the area where it is located hurts.

Attention! It is important to know that there is no such thing as laryngeal cartilage cancer. Sometimes this is popularly called stage III-IV laryngeal cancer, when the process itself has already affected the mucous membrane of the epiglottal cartilage.

In conclusion, it is important to note that knowledge of anatomy can not only help in providing emergency care, as in conicotomy, but also greatly facilitates the understanding of various pathological processes in this area.