Cricoid unpaired cartilage of the larynx: its structure and functions. Cricoid cartilage The main cartilages that make up the larynx

One of the anatomical structures of the upper respiratory tract is the larynx. To the layman, it appears to be a movable tube, which somewhere in its depth contains the vocal cords involved in the formation of the voice. Usually this is where knowledge ends. In fact, things are a little more complicated. Therefore, it is worth talking about this in more detail.

Topography

The larynx is located opposite the IV, V and VI cervical vertebrae, starting immediately behind and passing along the front surface of the neck. Behind her is the throat. It has a communication with the larynx through the entrance to the larynx, but in order to prevent food from entering the lungs, and air into the stomach, nature has provided such an important detail as the epiglottis, which closes the lumen of the pharynx during inhalation and shifts the larynx when swallowing, separating thus the functions of these organs.

On the sides of the larynx are large neurovascular bundles of the neck, and in front of all this is covered by muscles, fascia and the thyroid gland. From below, it passes into the trachea, and then into the bronchi.

In addition to the muscle component, there is also a cartilaginous component, represented by nine half-rings that ensure the reliability and mobility of the organ.

Features in men

A characteristic feature of the structure of the larynx in the representatives of the stronger sex is the presence of Adam's apple, or Adam's apple. This is a part that, for unknown reasons, is stronger in men than in women. Although it would be more logical to assume the opposite situation, because the muscular frame of the neck, which should cover the cartilage, is weaker in women.

Anatomy

The larynx is a cavity that is covered from the inside by a smooth and moist tissue - the mucous membrane. Conventionally, the entire cavity of the organ is divided into three sections: upper, middle and lower. The upper one is the vestibule of the larynx, they are narrowed down in the form of a funnel. The middle is the gap between the false and true vocal folds. The lower part serves to connect with the trachea. The most important and complex in structure department is the middle one. Here are the cartilages and ligaments of the larynx, thanks to which the voice is formed.

Voice education

The space between is called the "glottis". The contraction of the muscles of the larynx changes the tension of the ligaments, and the configuration of the gap changes. When a person exhales, air passes through the glottis, causing the vocal cords to vibrate. This is what produces the sounds we utter, in particular vowels. In order to pronounce a consonant sound, the participation of the palate, tongue, teeth and lips is also necessary. Their coordinated work allows them to speak, sing and even imitate the sounds of the environment and imitate the voices of other people or animals. The coarser one is explained by the fact that anatomically their ligaments are longer, which means they vibrate with a greater amplitude.

Ontogenesis

Depending on the age of a person, the structure of the larynx may also change. This is partly why men lose their voices after puberty. Newborns and infants have a short and wide larynx, it is located higher than that of an adult. It does not have horn-shaped cartilages and thyroid-hyoid ligaments. It will take its final form only by the age of thirteen.

The wall of the larynx

If we consider from a topographic point of view, then from the outside to the inside, its layers are arranged as follows:

• Leather.
• Subcutaneous tissue.
• Cartilage, ligaments, muscles.
• Fibrous-elastic membrane (represented by connective tissue).
• The mucosa is a multinucleated ciliated epithelium and fibers of unformed connective tissue that fuse with the previous layer.
• The outer connecting plate is elastic, covers the cartilages of the larynx.

Rigid frame of the larynx

As mentioned above, there is a phylogenetically formed apparatus that supports the larynx. The cartilages of the larynx are dense semicircles that hold the rest of the tissues of this area of ​​the neck and give the organ the appearance of a hollow tube. They are interconnected by ligaments. There are single and paired cartilages of the larynx.

Single cartilages

In the anatomy of the organ, there are three cartilages that do not have twins. Unpaired cartilages of the larynx are located along the same axis, one above the other.

1. The epiglottis, or epiglottis, is a thin plate shaped like a leaf or flower petal. The wide part is located above the thyroid cartilage, and the narrow part, also called the stalk, is attached to its inner corner.
2. The thyroid is the largest cartilage of the larynx, located between the epiglottis and the cricoid cartilage. Its name corresponds to both the form and function of this part of the organ. The thyroid cartilage of the larynx serves to protect its inner part from injury. It is formed by two quadrangular plates, fused in the middle. In this place, a crest is formed, on top of which there is an elevation to which the vocal cords are attached. On the sides of the plate have paired processes - horns (upper and lower). Those that are below articulate with the cricoid cartilage, and the upper ones with the hyoid bone. On the outer side of the cartilage there is an oblique line, to which the external muscles of the larynx are partially attached.
3. The cricoid cartilage of the larynx is an organ. Its shape is fully consistent with the name: it looks like a male ring, turned back with a signet. On the sides there are articular surfaces for connection with the arytenoid and thyroid cartilage. This is the second large cartilage of the larynx.

Paired cartilages

There are also three of them, since nature loves symmetry and seeks to show this love in every possible case:

1. Scoop. The arytenoid cartilage of the larynx is shaped like a trihedral pyramid, the top of which is turned back and slightly towards the center of the body. Its base is part of the surface of the joint with the cricoid cartilage. Muscles are attached at the corners of the pyramid: in front - the voice, and behind - the posterior and anterior cricoarytenoid muscles.
2. The corniculates are located above the tops of the arytenoid cartilages.
3. Cuneiform are usually located in scoop-epiglottic folds. The last two pairs of cartilage are sesamoid and can vary in shape and location.

All these formations give shape to such an organ as the larynx. The cartilages of the larynx perform the functions necessary to maintain normal human life. This is especially noticeable in relation to voice formation.

joints

As mentioned above, cartilage is interconnected through ligaments and joints. There are two paired joints in the larynx:

1. Between the cricoid and thyroid cartilage. They are formed by the lateral surfaces of the cricoid cartilage, which are adjacent to the lower horn of the thyroid. When moving in this joint, the tension of the ligaments changes, and consequently, the pitch of the voice.
2. Between the cricoid and arytenoid cartilages. It is formed by the articular surfaces (lower parts of the pyramid) of the arytenoid cartilages and the articular platform of the cricoid cartilage. Moving relative to each other, these anatomical formations change the width of the glottis.

Bundles

Being a mobile organ, ligaments have a great influence on how the larynx is arranged. The cartilages of the larynx are maintained in dynamic balance with the help of connective tissue strands:

1. The thyroid-hyoid ligament is part of the large thyroid-hyoid membrane that attaches the entire larynx to the hyoid bone. Through it passes the neurovascular bundle that feeds the organ.
2. The thyroid-epiglottic ligament connects the epiglottis to the thyroid cartilage.
3. Hyoid-epiglottic ligament.
4. The cricotracheal ligament connects the larynx to the trachea and attaches to the first cartilage of the larynx.
5. The conical ligament unites the cricoid and thyroid cartilages. In fact, it is a continuation of the elastic membrane that runs along the inner surface of the larynx. It is a layer between cartilage and mucosa.
6. The vocal fold is also part of the elastic cone that covers the vocalis muscle.
7. The aryepiglottic ligament.
8. The lingual-epiglottic ligaments unite the root of the tongue and the anterior surface of the epiglottis.

muscles

There are two larynxes. The first is functional. It divides all muscles into:

• Constrictors that narrow the glottis and larynx, making it difficult for air to pass through.
• Dilators needed to expand the larynx and glottis, respectively.
• Muscles capable of changing the tension of the vocal cords.

According to the second classification, they are divided into external and internal. Let's talk about them in more detail.

External muscles

External muscles wrap the larynx, as it were. The cartilages of the larynx are supported not only from the inside, but also from the outside. Conventionally, anatomists divide the outer group into two more: the first can include those muscles that are attached to the thyroid cartilage, and the second - those that are attached to the bones of the facial skeleton.

First group:

• sternothyroid;
• thyroid-hyoid.

Second group:

• sternohyoid;
• scapular-hyoid;
• stylohyoid;
• digastric;
• chin-hyoid.

Internal muscles

Necessary in order to change the position of the epiglottis and help it perform its functions, as well as to change the configuration of the glottis. These muscles include:

• aryepiglottic, which forms the aryepiglottic fold. During swallowing, the contraction of this muscle changes the position of the epiglottis in such a way that it blocks the entrance to the larynx and does not let food pass there.
• The thyroepiglottic, on the contrary, during contraction, pulls the epiglottis towards itself and opens the larynx.
• The lateral cricarytenoid regulates the width of the glottis. When it contracts, the ligaments converge and the glottis becomes narrower.
• The posterior cricoarytenoid contracts on inspiration, and the vocal folds open, pulling back and to the sides, allowing air to pass further into the airways.
• The vocal muscle is responsible for the characteristics of the vocal cords, how long or short they are, whether they are stretched or relaxed, whether they are the same in relation to each other. The timbre of the voice, its aberrations, and vocal abilities depend on the work of this muscle.

Functions of the larynx

The first of the functions, of course, is respiratory. And it consists in adjusting the air flow passing through the respiratory tract. Changing the width of the glottis prevents air from entering the lungs too quickly during inhalation. Conversely, air cannot leave the lungs too quickly until gas exchange has taken place.

The ciliated epithelium of the mucous membrane of the larynx takes on its second function - protective. It manifests itself in the fact that small particles of dust and food do not enter the lower respiratory tract due to the coordinated work of the cilia. In addition, the nerve endings, which are present in many on the mucosa, are very sensitive to foreign bodies and, when irritated, provoke a coughing fit. At this moment, the epiglottis blocks the entrance to the larynx, and nothing extraneous gets there. If the object still got into the larynx, the cartilages of the larynx reflexively interact with each other, and the glottis overlaps. This, on the one hand, prevents food and other bodies from entering the bronchi, on the other hand, blocks the access of air. If help does not arrive quickly, then the person dies.

The last one on our list is voice-forming. It is completely dependent on the anatomical structure of the larynx and on how much a person owns his vocal apparatus. In the process of growth and development, people learn to speak, sing, recite poetry and prose, imitate the voices of animals or the sounds of the environment, and sometimes even parody other people. The higher the level of control of your body, the more opportunities a person has.

This, in brief, is the normal topographic anatomy and physiology of the larynx. From the article, you learned about what an important function it performs in the activities of the human body and that the cartilage of the larynx plays an important role here. Thanks to her, we breathe normally, talk and do not choke every time we eat something. Unfortunately, it is more susceptible to infectious diseases and tumor processes than others.

The larynx is one of the most important organs, which is a flexible segment of the respiratory tract. It consists of fairly dense fabrics. The larynx lets air through, participating in breathing, it does not let liquid, food into the trachea. It also performs the function of sound production, since it is in the larynx that the vocal folds are located. The larynx is a hollow organ, the skeleton of which is cartilage, and the lining is smooth muscles and mucous membranes.

Features of the structure and function of the larynx

The special structure of the larynx allows it to perform several important functions. Thus, the air circulating in the cavity of the organ, contractions of the smooth muscles of the pharynx, muscles of the mouth and tongue, provide changes in the size and shape of the cavity, as a result of which the vocal cords are stretched. That is, by controlling the flow of air passing through the larynx, a person is able to reproduce sounds called speech.

In addition, it is the structure of the larynx, combined with the length of the vocal cords and muscles, that determines the pitch of the human voice and its timbre. If the voice becomes hoarse over time, this means that the ligaments lose their elasticity and firmness.

The structure of the larynx is such that all its elements are closely interconnected due to ligaments, membranes, cartilage and joints. Cartilaginous elements (as already mentioned) are the basis of the laryngeal cavity. They are the link between the hyoid muscles, the larynx itself, the thyroid gland and the respiratory system.

The laryngeal cartilages are presented two kinds:

• Unpaired;
• Paired.

Unpaired cartilages of the larynx

• Cricoid cartilage is the base of the larynx. It provides a link between the first ring of cartilage and the trachea. The cartilage has the form of a plate ("ring") and a tapering part ("arc"). The narrow part of the cricoid cartilage is directed forward, and the wide plate is located behind. At the top, the cricoid cartilage is united with the articular surface of the arytenoid, and on the sides with the thyroid cartilage, uniting with its lower horn;
• Thyroid- the largest cartilage of the larynx, which has the shape of two wide symmetrical plates, which, connecting at an angle, form an Adam's apple (laryngeal protrusion), which is perfectly palpable through the skin. Adam's apple in children and women has a slightly different shape and is much less pronounced than in men. The lower part of the thyroid cartilaginous element is provided with a recess, and behind, due to the thickening of the plates, the upper and lower horns are formed. The superior horn connects the thyroid cartilage to the hyoid bone and the inferior horn to the cricoid cartilage. The laryngeal artery runs through the thyroid cartilage.
• epiglottal. Located above the thyroid. Its shape is similar to a leaf of a tree, and therefore the upper part of the epiglottis is called a leaf, and the lower part is called a stalk. The "stalk" of the epiglottis is attached to the thyroid cartilage, and the "leaf" (that is, its wide part) descends to the root of the tongue.

Paired cartilages of the larynx

Ligament apparatus of the larynx

The laryngeal ligaments are responsible for the mobility of the cartilaginous elements and their connection to each other.

One of the largest and functionally important ligaments of the larynx is conical fold connecting the cricoid cartilage and the thyroid.

Another equally large thyrohyoid ligament located at the top between the hyoid bone and the larynx.

mucous membrane

The laryngeal mucosa is a continuation of the mucous membrane of the pharynx and nose, the upper layer of its main part is a cylindrical ciliated epithelium, and in the region of the vocal cords there is a squamous stratified epithelium. In some parts of the organ (false vocal folds, lingual surface of the epiglottis, subglottic space), the submucosal layer can be especially pronounced, which causes the development of edema, difficulty swallowing and breathing.

muscles

The muscles of the larynx are conditionally divided into: connecting it to the skeleton(thyroid-hyoid and sternothyroid) and organ's own muscle layer. Both the first and second muscle groups are striated.

Own laryngeal muscles are attached and begin on the laryngeal cartilages (more often at the back and side). There are several groups of the body's own muscles:

larynx cavity

The laryngeal cavity is conventionally divided into several sections:

• The vestibule (upper, vestibular) is located between the entrance to the larynx and the false vocal folds. From the sides, the vestibular region is bounded by aryepiglottic folds, and from above by the arytenoid cartilages and the epiglottis. In the folds of the vestibule there is a gap of the vestibule;
• Between the folds of the upper section and the two vocal folds is the shortest section of the larynx - the interventricular (or the region of the vocal folds). On each side of this department are the so-called "ventricles" - blinker's depressions. Slightly above the vocal folds are less developed "false" folds. The space between the "false" and true folds is the ventricles described above.

In the submucosal base of the larynx there is an elastic-fibrous membrane, which consists of an elastic cone and a quadrangular membrane. The lower part of the quadrangular membrane forms the left and right ligaments of the vestibule. The upper part of the elastic cone, stretched between the arytenoid cartilages (their vocal processes) and the thyroid cartilage, forms the vocal cords on each side of the larynx.

The whitish shade of the folds is formed due to the dense location on the surface of the cells of the squamous epithelium and the presence of an elastic membrane under it.

Breathing out voice. The air passing through the glottis causes the folds to vibrate, due to which the sound is born. The pitch and intensity of the sound depends on the tension of the ligaments and the speed with which the sound travels through the glottis.

At the very bottom of the larynx is the subvocal space (the third section of the organ) - this is a cone-shaped cavity that passes into the trachea. If the submucosal layer in the region of the subvocal space is loose, then the child may develop sudden swelling and an attack of "false croup".

The anatomy of the larynx is quite complex, which ensures the performance of all its functions - respiratory, voice formation. This organ is well supplied with blood, its entire surface is covered with a network of lymphatic vessels. Its structure implies the presence of several cartilages, muscles and mucous membranes.

Organ structure

The larynx is located near the cervical vertebrae. It connects the pharynx and trachea. The structure of the larynx implies that it consists of three layers of tissues:

• the mucous membrane covers the organ from the inside;
• the middle layer consists of striated muscles and cartilage, which are interconnected and form a hollow tube;
• outside the organ is covered with connective tissue.

On the front surface of the tube are the muscles of the neck, on the sides - a small part of the thyroid gland and large blood vessels, on the back side - the pharynx with the esophagus.

Features of the structure of the mucous membrane

The mucous membrane mainly consists of stratified ciliated epithelium. But in some places (the epiglottis, the edges of the vocal cords), subjected to significant mechanical stress, the surface is formed from a squamous epithelium.

The composition of the tissues lining the inner surface of the breathing tube includes connective structures. They can become inflamed, which leads to various diseases. Children are especially susceptible to this, because their connective tissue is especially developed.

The mucous membrane of the human respiratory tube consists of a large number of glands. They are evenly distributed over the entire surface of the body. There are also many lymphatic bodies here. Their most intense accumulation is observed in the ventricles of the larynx, where the tonsils are located.

muscles

The muscles of this organ are composed of striated fibers. They are evenly placed along the walls of the breathing tube.

Muscles can contract both voluntarily and reflexively. Depending on the functions, they are divided into the following types:

• constrictors. Able to narrow the glottis and the lumen of the respiratory tube;
• dilators. They differ in action opposite to constrictors - they work for expansion;
• a muscle group that can change the position and tone of the vocal cords;
• sternothyroid muscles, which can lower the larynx.

cartilage

The cartilages of the larynx make it mobile and flexible, which is possible due to the presence of special connections - joints, ligaments, membranes. All of them belong to hyaline. Only one epiglottis consists of more elastic tissues.

The structure of the larynx implies the presence of paired and unpaired cartilages. Each of them has its own structural features.

cricoid

The cricoid cartilage is the basis of the breathing tube. It consists of an arc and a wide quadrangular plate, with which it is turned back. With the help of joints, it connects to the thyroid and arytenoid cartilages.

Thyroid

The thyroid cartilage is the largest. It consists of several plates that are interconnected at a certain angle (depending on the gender of the person). This cartilage is located between the cricoid cartilage and the hyoid bone.

A notch is placed near the top edge. It is clearly visible on the neck and felt during palpation. The back of the cartilage has a continuation in the form of upper (attached by ligaments to the hyoid bone) and lower horns.

epiglottic

Has the shape of a petal. It consists of elastic tissue and is placed near the root of the tongue. The epiglottic cartilage closes the entrance to the larynx during meals. During a conversation, he, on the contrary, opens the lumen of the breathing tube. That is why talking while eating is dangerous, as it increases the risk of food particles entering the respiratory tract.

Other cartilage

• arytenoid cartilage. It has the shape of a trihedral pyramid, to which the vocal cords are attached;
• corniculate. The paired cartilages are in the shape of a cone and are located near the arytenoid cartilages;
• wedge-shaped. An elongated cartilage that blocks the entrance to the pharynx during swallowing.

joints

The structure of the larynx implies the presence of joints that provide its main functions.

cricoid-thyroid

It is the link between the cricoid and thyroid cartilage. This joint moves around a frontally placed axis. This provides an forward tilt of the thyroid cartilage.

cricoid-arytenoid

A paired joint located between two cartilages corresponding to the name. Moves around a vertical axis. This allows you to adjust the width of the glottis.

Voice apparatus

The anatomy of the larynx implies the presence in its composition of the vocal apparatus, represented by vocal cords attached to the thyroid and arytenoid cartilage.

The regulation of the work of this structure occurs due to the presence of muscles. They correct the shape of the glottis and the degree of tension of the ligaments, which affects the formation of voice.

The functional purpose of the body

The larynx is an important part of the human respiratory tract. It transports air down to the trachea, bronchi and lung tissue itself. This allows you to effectively carry out gas exchange and saturate the body with the necessary amount of oxygen.

The second function of the body is protective. It prevents foreign objects from entering the respiratory tract. Another purpose of the tube is sound production. Due to the peculiarities of its structure, when air flows, a person can speak.

What age-related changes does the organ undergo?

With age, this body undergoes some changes:

• in newborns, this organ is distinguished by a significant width, but a small length;
• in infants, the larynx is located slightly higher than in an adult;
• the entrance to the respiratory tube in newborns is much wider;
• in young children, there are no thyroid-hyoid ligaments and carob-shaped cartilages;
• the formation of the body ends at 13 years.

How is the male larynx different from the female?

The male larynx is significantly longer than the female, so the voice of the stronger sex is lower. This change in the structure of the body occurs during adolescence. It was then that there was a sharp jump in growth throughout the body. In women, the growth of the breathing tube occurs gradually, which does not cause such pronounced changes in the voice.

Another difference between the male larynx is the structure of the thyroid cartilage. Its plates are connected to each other almost at a right angle. This leads to the appearance of the so-called Adam's apple.

What diseases can affect the human larynx?

The human larynx can be affected by a variety of inflammatory processes that develop due to infection or allergies.

Acute laryngitis

Laryngitis is accompanied by inflammation of the mucous membrane of the larynx. This disease occurs due to the irritating action of many external or internal factors:

• dust and dirt;
• active reproduction of pathogenic bacterial flora;
• aggressive chemicals;
• allergic reactions of the body;
• reduced immunity.

Infiltrative laryngitis

The disease is accompanied by a bacterial lesion of the larynx along with ligaments, muscles and perichondrium. This occurs with an exacerbated course of infections or after injuries.

Other diseases

The larynx can also be affected by other diseases:

• angina with the spread of inflammation to the lymph nodes;
• swelling of the throat. It develops against the background of an allergic reaction of the body and is accompanied by a narrowing of the lumen of the respiratory tube;
• idiopathic edema. It develops against the background of acute infections and burns.

traumatic injury

Due to the intense mechanical impact on the larynx, cartilage fracture, dislocation or subluxation may occur. They are accompanied by intense pain, discoloration of the skin and shape of the neck. These conditions are extremely dangerous for the life of the victim, therefore, they require competent treatment.

Video: Larynx

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.

1. Cricoid cartilage, carrilago cricoidea. It is located at the beginning of the trachea and articulates with the thyroid cartilage. Rice. A, B, G.
2. Arc of the cricoid cartilage, arcus carrilaginis cricoideae. Forms the anterior and lateral parts of the cartilage. Rice. A, B.
3. Plate of the cricoid cartilage, lamina cartilaginis cricoideae. Turned back. Rice. A, B.
4. arytenoid articular surface, facies articularis arytenoidea. Obliquely oriented, oval-shaped facet, located laterally on the upper edge of the plate of the cricoid cartilage. Rice. BUT.
5. Thyroid articular surface, facies articularis thyroidea. A somewhat protruding articular facet at the junction of the arch and plate of the cricoid cartilage at its lower edge. Rice. BUT.
6. Cricothyroid joint, arriculatio cricothyroidea. Articulation between cartilages of the same name. In the joint, the rotation of the lower horns of the thyroid cartilage around the axis connecting both joints, as well as slight sliding of the cricoid cartilage relative to the thyroid cartilage, is carried out. Rice. B.
7. Cricothyroid joint capsule, capsula articularis crycothyroidea. Rice. B.

   7a. Horn-cricoid ligament, lig. ceratocricoideum. Thickening of the capsule, limiting movement. Rice. B.

8. Median cricothyroid ligament, lig. cricothyroideum medianum. A thick, vertically oriented cord located in the midline between the thyroid and cricoid cartilages. Rice. B, G.
9. Cricotracheal ligament, lig. cricotracheal. It is located between the cricoid cartilage and the first ring of the trachea. Contains elastic fibers. Rice. B, G.
10. arytenoid cartilage, carrilago arytenoidea. It has a pyramidal shape and is located above the cricoid cartilage. Rice. V, G.
11. Articular surface, facies articularis. It has a concave shape. It is located under the muscular process on the basis of the arytenoid cartilage and is intended for articulation with the cricoid cartilage. Rice. AT.
12. The base of the arytenoid cartilage, basis cartilaginis arytenoideae. Facing down. Rice. AT.
13. Anterolateral surface, facies anterolateralis. Place of attachment of muscles. Rice. AT.
14. Voice process, processus vocalis. Pointed forward. Attachment site of the vocal cord. Rice. AT.
15. Arcuate scallop, crista arcuata. It starts between the oblong and triangular pits, goes around the latter and ends at the mound. Rice. AT.
16. Hillock, colliculus. A slight elevation at the end of the arcuate scallop. Rice. V, G.
17. Oblong fossa, fovea oblonga. A recess in the anteroinferior section in front of the facies anterolateralis. Attachment site of the thyroid muscle. Fig.B.
18. Triangular fossa, fovea triangularis. Located above the oblong fossa. Filled with glands. Rice. AT.
19. Medial surface, facies medialis. Rice. AT.
20. Posterior surface, facies posterior. Rice. AT.
21. The apex of the arytenoid cartilage, apex cartilaginis arytenoideae. Curved backwards. Rice. V, G.
22. Muscular process, processus muscularis. Place of attachment of the posterior and lateral cricoarytenoid muscles. Directed backward and laterally. Rice. AT.
23. Cricoarytenoid joint, arriculatio cricoarytenoidea. Articulation between cartilages of the same name. In it, rotation of the arytenoid cartilage around the vertical axis and sliding to the sides are possible, as a result of which the distance between the two cartilages changes. Rice. G.
24. Cricoarytenoid joint bag, capsula articularis cricoarytenoidea. It is located between the arytenoid and cricoid cartilages, has a small thickness and is slightly stretched. Rice. G.
25. Cricoarytenoid ligament, lig. cricoarytenoidum. It connects the cartilages of the same name, contains elastic fibers, limits the movement of the arytenoid cartilage anteriorly. Rice. G.
26. Crico-pharyngeal ligament, lig. cricopharyngeum. The fibrous cord, which starts from the corniculate cartilage, is attached to the posterior surface of the cricoid cartilage plate and continues into the pharyngeal wall, located under the mucous membrane. Rice. G.
27. [Sesamoid cartilage, carrilago sesamoidea]. Small elastic cartilages in the anterior vocal cord and near its attachment to the arytenoid cartilage. Rice. G.
28. Cartilaginous cartilage [[Santorini cartilage]], carrilago comiculata []. Located at the top of the arytenoid cartilage. Rice. V, G.
29. Horn-shaped tubercle, tuberculutn corniculatum. A mucous-coated elevation at the apex of the arytenoid cartilage corresponding to the cartilage of the same name.