What muscles act on the entire larynx. Muscles of the larynx, their classification, functions. Innervation and blood supply of the larynx. posterior crestarytenoid muscle

Larynx, larynx, - located in the anterior region of the neck at the level of IV-VI cervical vertebrae. In front of the larynx are the muscles that lie below the hyoid bone; on the sides - vessels and nerves that form the neurovascular bundle of the neck; behind - the oral part of the pharynx; above - the hyoid bone, to which the larynx is suspended; below - the thyroid gland, as well as the trachea, into which the larynx directly passes. The larynx is the organ of sound production. It is built on the principle of an organ of movement, that is, it has: a skeleton formed by cartilage; cartilage joints - joints; ligaments; muscles that provide active mobility of cartilage.
Cartilages of the larynx, cartilagines laryngis, represented by three odd and three paired cartilages.
Thyroid cartilage, cartilago thyroidea, - unpaired, largest in size, hyaline, consists of two plates (right and left), lamina dextra et sinistra, connected in front at an angle. In men, the angle is acute (60-70 °), due to which a protrusion of the larynx is formed, prominentia laryngea. In women and children, this corner is rounded, due to which the performance is not expressed. In the middle of the upper and lower edges of the cartilage are the upper and lower thyroid notch, incisura thyroidea superior et inferior. The thickened posterior edge of each plate continues up and down, forming the upper and lower corners, cornu superius et inferius. The latter from the bottom from the inside has a surface for connection with the cricoid cartilage. On the outer surface of each plate contains an oblique line, linea obliqua, - the place of fixation of the sternothyroid and thyroid-hyoid muscles.
Cricoid cartilage, cartilago cricoidea, - unpaired, hyaline, has the shape of a ring, consisting of an arc, arcus cartilaginis cricoideae, and a plate, lamina cartilaginis cricoideae, facing backwards. The upper outer corner of the plate contains arytenoid articular surfaces, fades articularis aiytenoidea, for connection with arytenoid cartilages, and on the posterolateral surfaces of the arc, thyroid articular surfaces, fades articularis thyroidea.
Epiglottis, epiglottis, - unpaired, elastic, has the shape of a leaf-shaped plate. Its anterior surface faces the base of the tongue and is connected to the hyoid bone, and the edges to the arytenoid cartilages. The back surface faces the entrance to the larynx. Bottom part epiglottis narrowed in the form of a stalk, petiolus epiglottidis, joins the inner surface of the upper edge of the thyroid cartilage. A protrusion is formed in the lower part of the posterior surface, which is called the supraglottic tubercle, tuberculum epiglotticum.
arytenoid cartilage, cartilago arytenoidea, - paired, elastic, shaped like a pyramid, the base of which, basis cartilaginis arytenoideae, is associated with the plate of the cricoid cartilage, and the apex, apex cartilaginis arytenoideae, is directed upwards. There are three surfaces - medial, fades medialis, back, fades posterior and anterolateral, fades anterolateral. On the latter there is a tubercle, colliculus. From it, an arcuate ridge, crista arcuata, runs along the entire surface, which divides the surface into two pits - the upper triangular, fovea triangularis, and the lower oblong, fovea oblonga.
Two processes depart from the base of the cartilage - the lateral muscular, processus muscularis, and the anterior voice, processus vocalis.
cartilage, cartilago comiculata, - paired, elastic, located on the top of the arytenoid cartilage.
sphenoid cartilage, cartilago cuneiformis, - paired, located in front of the horn-shaped in the thickness of the aryepiglottic ligaments.
Between the cartilages of the larynx there are two pairs of joints that ensure the mobility of the cartilages and the change in the tension of the voice communication.
Cricothyroid joint, articulatio cricothyroidea, - located between the lower horns of the thyroid cartilage and the thyroid articular surfaces of the cricoid. It has a frontal axis of movement. The thyroid cartilage moves in this joint, changing its position relative to the arytenoid. In this case, the vocal cord, located between these cartilages, either tenses or relaxes.
Crico-arytenoid joint, articulatio cricoarytenoidea, - located between the base of the arytenoid cartilage and the arytenoid articular surface of the cricoid. It has a vertical axis of motion around which the arytenoid cartilage rotates. In this case, the vocal processes of both cartilages either approach or move away from each other. In addition, it is possible for the arytenoid cartilages to slide towards each other and in the opposite direction.
The corniculate cartilages are connected to the tops of the arytenoids by synchondrosis.
Between the cartilages of the larynx, as well as between the larynx and other organs, there are a number of syndesmoses:
1. Thyrohyoid membrane, membrana thyrohyoidea, - consists of the median thyroid hyoid ligament, ligamentum thyrohyoideym medianum, which stretches between the body of the hyoid bone and the upper edge of the thyroid cartilage (in the region of the superior thyroid notch) and the paired lateral thyroid hyoid ligament, ligamentum thyrohyoideum laterale, which runs between the greater angle hyoid bone and the upper edge of the plate of the thyroid cartilage, including the upper angle. In the thickness of the last ligament lies the granular cartilage.
2. Hyoid-epiglottic ligament, ligamentum hyoepiglotticum, - located between the body and horns of the hyoid bone and the middle of the anterior surface of the epiglottis.
3. Thyroid-epiglottic ligament, ligamentum thyroepiglotticum, - between the thyroid cartilage and the stalk of the epiglottis.
4. Cricothyroid ligament, ligamentum cricothyroideum, - between the arch of the cricoid cartilage and the lower notch of the thyroid. Consists of elastic fibers.
5. Cricotracheal ligament, ligamentum cricotracheale, - between the lower edge of the cricoid cartilage and the first ring of the trachea.
6. Cricoarytenoid ligament, ligamentum cricoarytenoideum, - a steam room connecting the cricoid and arytenoid cartilages, constitutes the lateral extension of the cricothyroid ligament.
7. Cricopharyngeal ligament, ligamentum ciicopharyngeum, - located between the plate of the cricoid cartilage and the pharynx.
8. vocal cord, ligamentum vocale, - steam room, consists of elastic fibers. Connecting the middle of the inner surface of the thyroid cartilage. In fact, this ligament constitutes the upper free edge of the elastic cone.
9. Ligament of vestibule, ligamentum vestibulare, - a steam room, located in the thickness of the fold of the same name above the voice connection and parallel to it.
Muscles of the larynx, musculi laryngis, are divided into three groups:
- Compressors - narrow the glottis or larynx cavity;
- Expanders - expand the glottis or larynx cavity;
- Muscles that change tension vocal cords.

Contractor muscles

Muscle expanders

Muscles that change the tension of the vocal cord

Age features of the larynx

X-ray anatomy of the larynx

Muscles of the larynx, mm. laryngis, striated; they can be divided into two groups.

1. Muscles whose function determines the movement of the entire larynx as a whole.
2. Own muscles of the larynx, which determine the movement of individual cartilages of the larynx.

The first group of muscles includes the muscles of the anterior group of the neck, which, according to their position in relation to the hyoid bone, can be divided into supra- and infrahyoid. They change the position of the hyoid bone, and with it the larynx, since the latter is connected with the hyoid bone with the help of membrana thyrohyoidea. The second group of muscles, lying between the cartilages of the larynx, determines the two main functions of the cartilages:

a) the function of the valve apparatus - a change in the position of the epiglottic cartilage during the act of swallowing and the act of breathing, and

The position of the epiglottic cartilage is changed:

1) Scoop-epiglottic muscle, m.. aryepiglotticus, mild; it starts from the muscular process of the arytenoid cartilage, goes obliquely and, crossing on rear surface arytenoid cartilage with the same muscle of the opposite side, follows to the top of the arytenoid cartilage of the other side. Further, heading anteriorly, it is woven into the lateral edges of the epiglottis. Being covered with a mucous membrane, it forms aryepiglottic folds, plicae aryepiglotticae, which limit the entrance to the larynx from the sides. The lower part of this muscle, extending from the muscular process to the top of the arytenoid cartilage of the opposite side, is described as an oblique arytenoid muscle. m.. arytenoideus obliquus. Reducing, m. aryepiglotticus narrows the entrance to the larynx and pulls back and downwards the epiglottic cartilage, thus closing the entrance to the larynx during the act of swallowing.

3. The thyroid-epiglottic muscle, m .. thyroepiglotticus, a thin, weak muscle, starts from the inner surface of the angle of the thyroid cartilage and, heading up and backwards, is attached to the anterior surface of the epiglottis. Contracting, it raises the epiglottis and thereby opens the entrance to the larynx during the act of breathing and speech; therefore it is also called a dilator of the vestibule of the larynx. The function of the vocal apparatus is performed by a number of muscles, which, according to this feature, can be divided into four groups:

1. The lateral cricoarytenoid muscle, m.. cricoarytenoideus lateralis, starts from the lateral surface of the cricoid cartilage and, heading obliquely upwards and backwards, is attached to the processus muscularis of the arytenoid cartilage. The muscle pulls the arytenoid cartilage to the side, as a result of which the vocal processes of the arytenoid cartilages, and hence the vocal cords attached to them, come closer and the size of the glottis decreases.
2. The transverse arytenoid muscle, m.. arytenoideus trans-versus, an unpaired, weak muscle, stretches between the posterior surfaces of both arytenoid cartilages. The muscle brings together the arytenoid cartilages and thus narrows the glottis, mainly in its posterior region.
3. The vocal muscle, m.. vocalis (see below), also takes part in the narrowing of the glottis. Muscles that expand the glottis. The posterior cricoarytenoid muscle, m .. cricoarytenoideus posterior, steam room, starts from the posterior surface of the cricoid, cartilage and, heading obliquely upward and laterally, is attached to the processus muscularis of the arytenoid cartilage. The muscle rotates the arytenoid cartilage so that the vocal processes of both arytenoid cartilages, and hence the vocal cords attached to them, move away from one another and thereby expands the glottis. Muscles that tense the vocal cords. The cricothyroid muscle, m.. cricothyroideus, steam room, is located on the anterolateral surface of the larynx, on the sides of the midline. It starts from the arch of the cricoid cartilage and, heading obliquely upward and laterally, is attached to the lower edge of the thyroid cartilage up to the lower horn. In the muscle, a straight part, pars recta, is distinguished, which is separated at the inferior thyroid tubercle from an oblique part, pars obliqua, located posteriorly and running almost horizontally. The muscle tilts the thyroid cartilage anteriorly, causing it to move away from the arytenoid cartilage and tense the vocal cords. Muscles that relax the vocal cords. The thyroarytenoid muscle, m.. thyroarytenoideus, is located horizontally in the anteroposterior direction, adjacent to the inner surface of the thyroid cartilage. The outer part of this muscle starts from the inner surface of the thyroid cartilage on the sides of the midline and, heading posteriorly, is attached to the anterolateral surface of the arytenoid cartilage in the region of the crista arcuata and fovea triangularis. The vocal muscle, m.. vocalis, is located medially from the previous muscle; has the appearance of a trihedral muscle protruding into the lumen of the larynx; it lies in the thickness of the vocal fold, plica vocalis. The muscle starts from the inner surface of the thyroid cartilage near the angle, goes posteriorly and attaches to the vocal process and fovea oblonga of the arytenoid cartilage. M. thyroarytenoideus as a whole, contracting, weakens the tension of the vocal cords and partly narrows the glottis. In the thickness of the fold of the vestibule there is an underdeveloped muscle stretched from the inner surface of the thyroid cartilage to the arytenoid. Contracting, it changes the tension of the fold of the vestibule.

The muscles of the larynx are formed by the striated muscle tissue, they are all paired, with the exception of the transverse arytenoid muscle. The muscles of the larynx are divided into two groups: external and internal. The external muscles fix the larynx and ensure its movement as a whole. These include:

1. sternothyroid muscle, it connects the outer surface of the larynx with the sternum, when contracted, causes the larynx to move down;
2. the thyroid-hyoid muscle connects the larynx to the hyoid bone, with contraction, the larynx moves upward.

The internal muscles of the larynx or the laryngeal proper change the position of individual cartilages relative to each other, and, accordingly, the tension of the vocal cords and the width of the glottis. They are divided into three groups:

1. Thyroarytenoid muscle lies in the thickness of the vocal folds, laterally from the vocal cords (Fig. 22). In this muscle, two parts are distinguished - the inner, which is called the vocal muscle, and the outer. The anterior ends of the thyroarytenoid muscle are attached to the inner posterior surface of the thyroid cartilage, in the angle formed by its plates, the posterior ends of the vocal muscle are attached to the vocal process, and the fibers of the outer part of this muscle are attached to the muscular process of the arytenoid cartilage. The vocal muscle fibers run in different directions and are partially woven into the vocal cord. Some of its bundles start directly from the vocal cord. When contracted, it causes tension of the vocal cords as a whole or their individual sections and a slight narrowing of the glottis, which causes the appearance of sounds of different heights (just as pressing a guitar string with a finger in different places gives it a different sound).

2. Cricothyroid muscle, with one end attached to the outer surface of the cricoid cartilage arc, the other end - to the lower edge of the plate of the thyroid cartilage (Fig. 23, 24). During contraction, the thyroid cartilage leans forward and downward, moving away from the arytenoid cartilages, thereby contributing to the tension of the vocal cords and narrowing of the glottis.

The group of muscles that expand the glottis includes only the posterior cricoarytenoid muscle - the most strong muscle larynx (for brevity, this pair of muscles is called the back). The muscle begins on the posterior surface of the cricoid cartilage plate and attaches to the muscular process of the arytenoid cartilage. Right and left muscle, contracting at the same time, they pull back the muscular processes, the arytenoid cartilages rotate around the vertical axis, while the vocal processes of the cartilages, together with the vocal cords attached to them, diverge to the sides, and the glottis expands (Fig. 24, 25).

1. Lateral (lateral) cricoarytenoid muscles- antagonists of the posterior cricoarytenoid muscle. The muscle starts from the upper edge of the lateral part of the cricoid cartilage and is attached to the muscular process of the arytenoid cartilage. During contraction, it pulls the muscular process forward, and the vocal process moves to the midline and narrows the glottis (Fig. 26).

2. Transverse arytenoid muscle (or simply transverse)- the only unpaired muscle of the larynx. Its fibers are located transversely, and connect the posterior surfaces of the arytenoid cartilages to each other (Fig. 24). During contraction, the muscle brings these cartilages together, contributing to the closure of the glottis.

3. Oblique arytenoid muscles complement the action transverse muscle. Their fibers run in an oblique direction and connect the muscular process of one arytenoid cartilage with the top of the other. The right and left muscles cross each other (Fig. 24). During contraction, the arytenoid cartilages are brought together, narrowing the glottis.

Innervation of the larynx

The innervation of the larynx is carried out by two branches of the vagus nerve (X pair) - the upper laryngeal and lower laryngeal nerves. The superior laryngeal nerve contains predominantly sensory fibers and innervates most of the mucous membrane of the larynx. The inferior laryngeal nerve carries out mainly motor innervation. internal muscles larynx. Through the central nervous system The larynx is connected to various parts of the body. Painful irritations, emotional arousal can cause a change in voice, sometimes even aphonia.

Posterior cricoarytenoid muscle.

2. Muscles that narrow the glottis (constrictors):

Lateral cricoarytenoid muscle and cricothyroid muscle

Oblique and transverse arytenoid muscles.

3. Muscles that change the tension of the vocal cords:

Cricothyroid muscle

The work of the muscles of the larynx together with the vocal cord provides voice formation. The vocal cord can be compared to a string that vibrates and makes a sound when a stream of air passes. It should be emphasized that only the formation of sound occurs in the larynx. Lips, tongue, soft palate, paranasal sinuses take part in articulate speech.

Blood supply of the larynx happens due to superior thyroid artery, which is a branch of the external carotid artery, and lower thyroid arteries- a branch of the thyroid trunk. from the superior thyroid artery superior and middle laryngeal arteries. From the inferior thyroid artery inferior laryngeal artery. Venous outflow is carried out through the veins of the same name (associated arteries) during internal jugular vein.

Innervation of the larynx carried out two branches of the vagus nerve. superior laryngeal nerve is a mixed nerve. It departs from the lower node of the vagus nerve goes down and, not reaching the hyoid bone, is divided into two branches: a) outdoor, which is a motor branch and innervates the only muscle of the larynx - the anterior cricoid, and the lower constrictor of the pharynx; b) internal, which penetrates into the lumen of the larynx through a hole in the thyroid-sublingual membrane and provides a sensitive innervation of the mucous membrane of the larynx.

Trachea The hollow organ of the trachea divides into two main bronchi

The place where the trachea divides is called bifurcation(doubling).

Function of the trachea air conduction.

The wall of the trachea consists of four membranes.

mucous membrane lined with ciliated pseudostratified epithelium containing a large number of goblet cells.

Submucosa, gradually passes into a dense fibrous connective tissue - the perichondrium of the trachea.

Fibrous-muscular-cartilaginous shell The trachea is formed by 16-20 hyaline cartilages, each of which is a half ring, open posteriorly. The cartilages are interconnected by annular ligaments.

adventitial sheath made up of loose fibrous connective tissue.

main bronchi start directly from the trachea. There are right and left main bronchi. The right main bronchus is wider and shorter than the left, in direction it is almost a continuation of the trachea. The left main bronchus is narrower and longer than the right. The aortic arch bends through the left main bronchus, and the unpaired vein through the right one. The main bronchi enter the gates of the lungs. The wall of the main bronchi is arranged in the same way as the wall of the trachea.

Blood supply to the trachea provide inferior thyroid arteries.

Innervation - recurrent laryngeal nerves.

Blood supply of the bronchi carried out bronchial arteries, departing from thoracic aorta

Innervation - branches of the vagus, sympathetic and spinal nerves.

Lungs, their position, structure, functions, blood supply andinnervation.

Lungs(right and left) are located in the chest cavity, on the sides of the heart. From below they border on the diaphragm, on the sides with the ribs, upwards the lungs rise above the 1st rib by 3-4 cm. Lung functions: air conduction (bronchial tree) and gas exchange (alveolar tree). The lung is shaped like a cone, so it is distinguished top and base. Each lung has three edges - front, bottom and rear and three surfaces diaphragmatic, costal and mediastinal(adjacent to the organs of the mediastinum). On the mediastinal surface of each lung there is a recess - the gate of the lung, where the main bronchus of the artery and nerves enter, and the pulmonary veins and lymphatic vessels exit.

Left lung narrower and longer than the right. On its front edge there is a cardiac notch, which ends below with a pulmonary uvula. In addition, the left lung, unlike the right one, consists of two lobes - upper and lower, separated by an oblique fissure.

Right lung shorter and wider than the left, as the liver presses on it from below. It consists of three lobes - upper, middle and lower, separated by oblique and horizontal slits.

Lung- this is a parenchymal organ, covered on the outside with a visceral pleura, very closely fused with the lung parenchyma. The connective tissue of the pleura enters the parenchyma, dividing it into lobes, then segments and lobules.

Arterial supply lung tissue, except for the alveoli, is carried out bronchial arteries, departing from thoracic aorta.

The pulmonary arteries and veins perform the function of blood oxygenation, providing nutrition only to the terminal alveoli.

Deoxygenated blood from the tissue of the lung, bronchi and large vessels flows along bronchial veins entering the system superior vena cava, and also partly in pulmonary veins.

Lung innervation carried out branches of the vagus, sympathetic, spinal and phrenic nerves, forming anterior and posterior pulmonary plexus.

Anatomical characteristics of the organs of the urinary system. Age features.

urinary system performs the functions of purifying the blood, forming urine and excreting harmful substances from the body along with it.

The urinary system is made up of kidneys, ureters, bladder and urethra.

kidneys in newborns and infants, they are rounded, their surface is bumpy due to the lobular structure (there are 10-20 lobules), which is associated with insufficient development of the cortical substance. The length of the kidneys at birth is 4.2 cm, weight - 12 g. In infancy, the size of the kidneys increases 1.5 times, and the weight - 3 times (37 g).

Kidney growth occurs unevenly, it is most intense in the first year of life. In the period of 5-9 years, and especially at 16-19 years, the size of the kidneys increases due to the development of the cortical substance, the growth of the medulla stops by the age of 12. The thickness of the cortical layer of an adult, compared with that at birth, increases by 4 times, and that of the medulla - by 2 times.

Ureters and bladder. By the time of birth, the ureters are sinuous, up to 7 cm long. By the age of 4, their length reaches 15 cm. The capacity of the bladder increases from 50-80 to 500 cm3 in an adult.

In old age and old age there is a decrease in the mass of the kidneys. As a result of impaired hemomicrocirculation, there is a progressive decrease in the number of renal glomeruli. Changes also affect other parts of the nephrons. The blood flow in the vessels of the kidneys worsens, connective tissue grows in the cortical substance. The dynamics of urine flow from cups to the pelvis and ureters is disturbed. Uric acid salts are deposited in the kidneys, forming stones and sand. The ureters also lose elasticity. As a result of atrophy of the muscular membrane, their walls expand, deform, the tone of the sphincters decreases, and the function weakens. These changes exacerbate the processes of stone formation in the kidneys.

Decreased bladder distensibility in old age leads to an increase in the frequency of urination. Difficulty urinating in men contributes to the development of prostate adenoma, which compresses the initial section of the urethra. Urinary incontinence in the elderly is due to the weakness of the sphincters and impaired innervation.

Nephron, its structure, functional significance.

Nephron- structural and functional unit of the kidney. The nephron consists of a renal corpuscle, where filtration occurs, and a system of tubules, in which reabsorption (reabsorption) and secretion of substances take place.

In humans, each kidney contains about a million nephrons, each about 3 cm long.

Each nephron contains six divisions, greatly differing in structure and physiological functions: renal corpuscle (Malpighian corpuscle), consisting of Bowman's capsule and renal glomerulus; proximal convoluted renal tubule; descending limb of the loop of Henle; ascending limb of the loop of Henle; distal convoluted renal tubule; collecting duct.

Renal body. The nephron begins with the renal corpuscle, which consists of the glomerulus and Bowman-Shumlyansky's capsule. Here, ultrafiltration of blood plasma takes place, which leads to the formation of primary urine.

proximal tubule- the longest and widest part of the nephron, conducting the filtrate from the Bowman-Shumlyansky capsule into the loop of Henle.

Loop of Henle- part of the nephron that connects the proximal and distal tubules. The loop has a hairpin bend in the renal medulla. The main function of the loop of Henle is the reabsorption of water and ions in exchange for urea by a countercurrent mechanism in the medulla of the kidney.

Kidneys, their position, shape, functions, blood supply and innervation.; 22. Kidneys, their internal structure. Blood supply and innervation.

The kidneys (right and left) are bean-shaped and weigh 150-200 g. The kidney of an adult is 10-12 cm long, 5-6 cm wide and up to 4 cm thick. The kidneys are located on the back wall of the abdominal cavity in lumbar region in a special renal bed formed by the square muscle of the lower back. The right kidney is located slightly lower than the left, as the liver presses on it from above.

The kidney is a parenchymal organ. On the frontal section of the kidney in the parenchyma, the cortex and medulla are distinguished, as well as the renal sinus located in the center.

The kidneys are not covered by the peritoneum, so they have their own fixing device.

Contractor muscles

1. Lateral cricoarytenoid muscle, musculus cricoarytenoideus lateralis, - steam room, originates from the arc of the cricoid cartilage and is attached to the muscular process of the arytenoid. When contracting, it pulls the muscle process forward and down. The vocal processes at the same time approach each other, and the glottis narrows.

2. Thyroid arytenoid muscle, musculus thyroarytenoideus, - steam room, originates from the inner surface of the plate of the thyroid cartilage, passes up and back, attaches to the muscular process of the arytenoid cartilage. With the contraction of both muscles, the part of the cavity of the larynx above the vocal cords narrows. At the same time, the arytenoid cartilages are pulled forward and the vocal cords relax somewhat.

3. transverse arytenoid muscle, musculus arytenoideus transversus, - unpaired, connecting both arytenoid cartilages. When the muscles contract, the cartilages come together, the glottis narrows.

4. Oblique arytenoid muscle, musculus arytenoideus obliquus, - steam room, originates from the muscular process of the arytenoid cartilage, passes obliquely upwards, intersects with the muscle of the same name on the opposite side, attaches to the top of the arytenoid cartilage on the opposite side. When contracted, it narrows the back of the glottis.

5. The arytenoid-epiglottic muscle, musculus aryepiglotticus, is a steam room, originates from the top of the arytenoid cartilage, is a continuation of the previous muscle. Passes in the thickness of the aryepiglottic fold, attaches to the lateral edge of the epiglottis. Narrows the entrance to the larynx and pulls the epiglottis down.

Muscle expanders

1. Thyroid epiglottis muscle, musculus thyroepiglotticus, - steam room, originates from the inner surface of the plate of the thyroid cartilage, lies on the side of the thyroid-epiglottic ligament, attaches to the edge of the epiglottis, passes partially into the arytenoid-epiglottic fold. Expands the entrance to the larynx and its vestibule.

2. Posterior cricoarytenoid muscle, musculus cricoarytenoideus posterior, - steam room, originates from the posterior surface of the plate of the cricoid cartilage, attaches to the muscular process of the arytenoid. During contraction, it pulls the muscular process back and medially, as a result of which the vocal process returns laterally and the glottis expands.

1. vocal muscle, musculus vocalis, - steam room, originates from the inner surface of the thyroid cartilage, attaches to the vocal process of the arytenoid. The medial edge of the muscle is fused with the vocal cord, and the lateral edge is adjacent to the thyroarytenoid muscle. When contracted, it pulls the vocal process forward. In this case, the vocal cords relax, and the glottis narrows slightly.

2. Cricothyroid muscle, musculus cricothyroideus, - steam room, originates from the middle of the cricoid cartilage arc, attaches to the lower edge (straight part, pars recta) and the lower corner (oblique part, pars obliqua) of the thyroid cartilage. When contracted, it pulls the thyroid cartilage forward, which causes tension in the vocal cords.
The wall of the larynx is formed by its cartilage (united with the help of ligaments, joints, muscles), fibrous-elastic membrane, mucous membrane, outer connective tissue membrane.

Fibrous elastic membrane of the larynx, membrana fibroelastica laryngis, lies under the mucous membrane of the larynx. At the level between the upper edge of the cricoid cartilage, the lower notch of the thyroid cartilage and the vocal processes of the arytenoids, this membrane narrows from bottom to top, forming an elastic cone, conus elasticus.

mucous membrane, tunica mucosa, is lined with stratified ciliated epithelium, with the exception of the vocal folds covered with stratified squamous non-keratinized epithelium. The epiglottis is also lined with stratified squamous non-keratinized epithelium, since here the mucous membrane of the larynx borders on the mucous membrane of the digestive apparatus. The submucosa contains the laryngeal glands and lymphoid nodules.

Outer connective tissue sheath covers the cartilages of the larynx, contains many elastic fibers, is actually part of the visceral plate of the internal fascia.

larynx cavity, cavitas laryngis, makes up a kind of tube, expanded from above and below, narrowed in the middle, i.e. resembles an hourglass. The cavity begins with the entrance to the larynx, aditus laiyngis, which is bounded in front by the epiglottis, on the sides by arytenoid-epiglottic folds, plicae aryepiglotticae, and behind by the tops of the arytenoid cartilages.

The upper expanded part of the larynx cavity is called the vestibule, vestibulum laryngis. It extends from the entrance to the larynx to the doorway folds, plicae vestibulares, which limit the gap of the vestibule. The mucous membrane of the vestibule of the larynx is very sensitive - its irritation reflexively causes a strong cough.

The middle narrowed part of the larynx extends from the doorway to the glottis, formed by the vocal folds, plicae vocales.
The glottis is the narrowest part of the larynx. It has two parts. The anterior, limited by areas of the vocal folds containing the vocal cords and muscles, is called the intermembranous part, pars intermembranacea. The back, limited by areas of the vocal folds, in the thickness of which the vocal processes of the arytenoid cartilages lie, is called the intercartilaginous part, pars intercartilaginea. A recess is formed between the parietal and vocal folds - the ventricle of the larynx, ventriculus laryngis.

The lower expanded part of the larynx is the subvocal cavity, cavitas infraglottica. Tapering downward, it passes into the trachea. When examining the cavity of the larynx (laryngoscopy) in a living person, you can see the vestibules and vocal folds, assess the condition of the mucous membrane, the width of the glottis. The mucous membrane looks smooth, has a uniform pink color, and in the area of ​​the parietal folds it is reddish.
During quiet breathing, the glottis is wide enough, and during sound production (phonation), it periodically narrows and can even close. Sound production occurs due to the fact that active vibrations of the vocal cords during exhalation cause the appearance of oscillatory air waves. The sound formed in the larynx is amplified and gains a characteristic color (timbre) in the resonators - the upper respiratory tract, oral cavity, and paranasal sinuses.