about the project
Medical news
For authors
Licensed books on medicine
<< Previous Next >>

Clinical physiology of the pharynx

The pharynx is part of the digestive and respiratory tract; food and saliva pass through it into the gastrointestinal tract, and air into the larynx, lungs, and vice versa. She takes part in the following vital functions: the act of eating - sucking and swallowing; voice and speech education; act of breathing; protective mechanisms during eating and breathing, as well as in taste function.

For example, in the first months of a child’s life, it is possible only with the help of a motor activity. When sucking, the organs of the oral cavity create negative pressure within 100 mmHg. The soft palate at the time of sucking is pulled down and draws closer to the root of the tongue, closing the oral cavity behind, which allows you to breathe through your nose. When sucking, the tongue pressed to the bottom of the oral cavity is retracted, while the lower jaw drops and the oral cavity increases. After the fluid is sucked into the oral cavity, sucking and breathing are interrupted and an act of swallowing occurs, then breathing resumes and the fluid is again sucked into the oral cavity. In adults, after chewing in the area of ​​the root of the tongue, a food lump forms. The pressure that arises in this case causes an act of glottany - a peristaltic contraction of the muscles compressing the pharynx, the muscles of the soft palate and palatine arches. As a result of this complex coordinated reflex act, during which breathing is held in a certain sequence, muscles of the tongue, pharynx, and larynx are contracted, which ensures the passage of food from the oral cavity through the pharynx to the esophagus.

The first phase of the act of winding is arbitrary; by lifting the tongue, the food lump advances beyond the front temples.

The second phase — the advancement of the food lump through the pharynx to the entrance to the esophagus — is involuntary, provided by a congenital reflex. If the reception of the mucous membrane of the upper pharynx is affected, the act of swallowing may be disturbed, since the reflex arc is interrupted. A similar phenomenon can be observed with severe anesthesia of the pharyngeal mucosa. At the beginning of the second phase, the larynx rises, the epiglottis is pressed to the root of the tongue and lowers, closing the entrance to the larynx; the arytenoid cartilages come together, as well as the vestibular folds, narrowing the vestibular part of the larynx. As a result of contraction of the muscles of the palatine arches, the upper muscle compressing the pharynx, the food lump moves into the middle part of the pharynx. At the same time, the soft palate rises, is pulled back and pressed against the back wall of the pharynx, thereby separating the nasopharynx from the oropharynx. In the middle section of the pharynx, the middle and lower compressors cover the food lump and advance it downward. By raising the larynx, hyoid bone and pharynx, the advancement of the food lump is facilitated.

The third phase of swallowing is a continuation of the second: the approach of the food lump to the entrance to the esophagus causes a reflex opening of its entrance ("mouth" of the esophagus) and the lump moves actively along the esophagus due to peristaltic contraction of its muscles. After the pharynx is released from the food lump, the initial position is restored. The act of swallowing in a person lasts several seconds. Eating affects many physiological functions of the body: respiration, blood circulation, gas exchange, the functioning of the motor apparatus.

On the front and back surfaces of the soft palate, the posterior walls of the pharynx and epiglottis there is a small number of diffuse taste buds, but they do not have significant significance for taste sensitivity (in comparison with those on the tongue).

The recipe for pharynx consists in resonating sounds arising in the larynx.
The formation of the timbre of the voice occurs in the cavities of the larynx, pharynx, nose, paranasal sinuses and mouth. The following circumstances contribute to the strengthening and “coloring” of the voice: the volume and shape of the pharyngeal cavity can change, and the soft palate is characterized by considerable mobility and can change the direction of movement of sound vibrations (into the mouth and nose). The larynx creates a sound of a certain height and strength, and the formation of vowels and consonants occurs mainly in the mouth and to a lesser extent in the pharyngeal cavities. When pronouncing vowels, the soft palate blocks the nasopharynx from the oral cavity, while consonants are pronounced when the soft palate is lowered.

All its departments are involved in the extraction of the pharynx and pharynx, however, in case of violation of the patency of the nose, breathing occurs through the mouth, and in this case, as well as partially during conversation, singing, etc. d. the air does not pass through the nasopharynx, but immediately enters the middle part of the pharynx.

The protection of the pharynx is expressed in the fact that when a foreign body or substances with pronounced irritating properties (chemical and thermal effects) get into it, the reflex contraction of the muscles of the pharynx occurs and its lumen narrows As a result, deeper penetration of the irritating substance is delayed. In the pharynx, the air entering it from the nasal cavity continues to be warmed and cleaned of dust, which adheres to the mucus covering the walls of the pharynx, and with it is removed by expectoration or swallowed and neutralized in the gastrointestinal tract. White blood cells and lymphocytes penetrating the oral cavity and pharynx from the blood vessels of the mucous membrane and lymphadenoid tissue also play a protective role. Good blood supply to the mucous membrane of the pharynx, as well as the bactericidal properties of saliva, contribute to the healing of damaged tissues in the mouth and pharynx.

The physiology of the tonsils is not autonomous, characteristic only of these lymphoid formations. The function of the palatine and other tonsils of the pharynx can be characterized in the physiological system of the lymphatic organs of the whole organism. Three groups of lymphoid structures are distinguished: lymphoid tissue of the spleen and bone marrow — the blood and lymph barrier; lymph nodes with adducting and abducting vessels - the lympho-interstitial barrier; tonsils, all lymphoid pharyngeal formations that do not have adducting lymphatic vessels, Peyer's plaques and solitary intestinal follicles - the lymphoepithelial barrier. All three groups of lymphoid structures of the body have the same general structure. In the lymphadenoid (lymphatic) pharyngeal ring (all lymphoid structures) are characterized by anatomical and histomorphological similarities and functional synergies. These data indicate the absence of specific functional palatine (or other) tonsils.

In the first years of life, the lymphoid structures of the pharynx reach their greatest development, and from the moment sex hormones (from 14-15 years old) appear, they gradually reverse develop. In the tonsils of the pharynx lymphocytes are formed, which are secreted into the oral cavity and pharynx. In the tonsils there is a mild formation of antibodies. As in all lymphoepithelial structures, in the tonsils, lymphocytes and neutrophils constantly migrate through the integumentary epithelium. Lymphocytes, once in the oral cavity and pharynx, are destroyed and secrete enzymes that are involved in oral digestion.
<< Previous Next >>
= Skip to textbook content =

Clinical physiology of the pharynx

    The pharynx has the following functions: swallowing, respiratory, protective, resonant, speech. The swallowing function (according to Magendie) is provided by two acts. Initially, with the approach of a food lump or saliva, the muscles of the amygdala arches (m. Palatoglossus et palatopharyngeus) and the muscles of the root of the tongue contract, pushing the contents further from the oral cavity to the oropharynx. The back muscles are included here.
    The pharynx, pharynx, is the initial part of the digestive tube located between the oral cavity and the esophagus. At the same time, it is also part of the respiratory tube, connecting the nasal cavity or oral cavity with the larynx. Consequently, in the pharyngeal cavity, the digestive and respiratory tract cross. The pharynx has the shape of a funnel-shaped tube flattened in the anteroposterior direction,
  4. Clinical pharyngeal anatomy
    The pharynx (pharynx) enters the initial section of the digestive tract and respiratory tract. It is a hollow organ formed by muscles, fascia and lined with mucous membrane from the inside. The pharynx connects the nasal and oral cavities with the larynx and esophagus, through the auditory tubes the pharynx communicates with the middle ear. The pharyngeal cavity is vertically projected onto the bases of the occipital and wedge-shaped
  5. Clinical anatomy and topography of the pharynx. Pharyngeal and periopharyngeal spaces
    The pharynx (pharynx) is the initial section of the digestive tract and respiratory tract. Three sections are distinguished in the pharynx: 1. Upper - nasopharynx, 2. Middle - oropharynx. 3. The lower is the larynx. The nasopharynx performs a respiratory function. At the top, the nasopharynx arch is fixed to the base of the skull, behind the nasopharynx it borders on the I and II cervical vertebrae, in front are the choanas, on
  6. Clinical physiology
    Indicators of pulmonary function (adult 70 kg) {foto13} {foto14} Fig. 3. Static and dynamic lung volumes 1 - total lung capacity (TLC); 2 - vital lung capacity (VC); 3 - reserve inspiratory volume (IRV); 4 - reserve expiratory volume (ERV); 5 - residual lung capacity (RV); 6 - functional residual lung capacity (FRC); 7 - tidal volume (VT);
  7. Clinical anatomy and physiology of the esophagus
    The esophagus (oesophagus) is a continuation of the pharynx from the level of the lower edge of the cricoid cartilage (CV]) and is a flattened anteroposterior muscle tube 24-25 cm long. The esophagus passes into the stomach at the Thxi level, which corresponds to the site of attachment of the VII costal cartilage to the sternum. The total distance from the front teeth (through the mouth, pharynx and esophagus) to the stomach
    The physiology and pathophysiology of the respiratory system can only be considered in the context of the life of the whole anatomical and physiological complex, which provides the process of external respiration, which includes extrapulmonary and pulmonary structures. Extrapulmonary structures include: 1. CNS regulatory structures (certain zones of the cerebral cortex, reticular formation, oblong
  9. Clinical physiology of the ear
    Clinical physiology
  11. Clinical physiology of the liver
    Currently, about 500 metabolic functions of the liver are known, the main of which are the following: 1. Participation in protein metabolism. In the liver, both anabolic (synthetic) and the main catabolic processes of protein metabolism are carried out. Protein synthesis comes from free amino acids coming from three sources: a) exogenous free amino acids delivered from the blood
  12. Clinical physiology of the nose and paranasal sinuses
    Distinguish between upper and lower respiratory tract. The nose and paranasal sinuses, the pharynx with the oral cavity and the larynx belong to the upper respiratory tract, the trachea, bronchi with bronchioles of the alveoli - to the lower. Normal for a person is breathing through the nose. The nose performs, in addition to the respiratory, protective, resonant and olfactory functions, and also participates in the regulation of the depth of breathing and lacrimation,
    Otorhinolaryngology is a science and practical discipline about diseases of the ear, nose, pharynx and larynx (abbreviated as ENT). Given the applied nature of the manual, it is advisable to provide the main content - a description of the diseases - with information on the clinical anatomy, physiology and research methods of these organs. Since diseases of ENT organs are often interconnected with pathology nearby
    The embryo of the inner ear at the embryo appears earlier than the rudiments of the outer and middle ear — at the beginning of the 4th week of fetal development, it forms in the area of ​​the rhomboid brain in the form of a limited thickening of the ectoderm. By the 9th week of fetal development, the formation of the inner ear ends. The cochlear apparatus is phylogenetically younger and develops later than the vestibular apparatus. However processes
Medical portal "MedguideBook" © 2014-2019