Throat - cylindrical, slightly flattened in the sagittal direction funnel muscular tube length of 12 to 14 cm, placed in front of the cervical vertebrae. Body pharynx (upper wall) is connected
with the base of the skull, the back is attached to the occipital bone, the lateral part - to the temporal bone and the lower part goes into the esophagus at the level of the sixth vertebra of the neck.
Throat - a place of crossing respiratory and digestive tracts. Food mass from the oral cavity during the swallowing process enters the throat, and then into the esophagus. The air from the nasal cavity through hoany either from the oral cavity through the throat and enters the throat, and further the larynx.
The structure of the pharynx
The anatomy of the pharynx are three main parts - the nasopharynx (the upper part), the oropharynx (the middle part) and the hypopharynx (lower part). Oropharynx and nasopharynx are connected to the oral cavity, hypopharynx and larynx is associated with. The pharynx connects to the throat through oral, nasal cavity with it communicates through the choanae.
Oropharynx - the continuation of the nasopharynx. The soft palate, palatine arch and back of the tongue is separated from the oropharynx oral cavity. The soft palate is lowered directly into the pharyngeal cavity. During swallowing and pronouncing sounds skies lifted up, thereby providing articulate speech and preventing food from entering the nasopharynx.
Hypopharynx begin in the fourth or fifth vertebra, and gradually going down, it goes into the esophagus. The front surface of the hypopharynx represented the area where is located the lingual tonsil. Once in the mouth, the food is crushed, then the bolus passes through the esophagus into the hypopharynx.
On the side walls of the pharynx located funnel-shaped opening of the auditory (Eustachian) tube. This structure helps to balance the throats of atmospheric pressure in the tympanic cavity of the ear. In the area of these holes are placed in a tube almonds paired clusters of lymphoid tissue. Such clusters exist in other parts of the pharynx. Lingual, pharyngeal (adenoid), two pipe, two palatine tonsils form lymphoid ring (Pirogov - Valdeyera). Lymphoid ring prevents the penetration of the human body of foreign substances or microbes.
Pharyngeal wall consists of a muscular layer, the adventitia and mucous membranes. The muscle layer is represented by a group of muscles of the pharynx: stylopharyngeus muscle that raises the larynx and pharynx and arbitrary paired striated muscle - the upper, middle and lower pharyngeal constrictor, narrows its lumen. When swallowing efforts longitudinal pharyngeal muscles rises, and striated muscles, consistent cutting, pushing the bolus.
In the mucosa and muscular layer is submucosa with fibrous tissue.
various different locations on the structure. In the oropharynx and hypopharynx mucosa is covered by stratified squamous epithelium, and in the nasopharynx - ciliated epithelium.
The functions of the pharynx
The pharynx is involved in several vital functions: eating, breathing, phonation, protective mechanisms.
The respiratory function involving all parts of the pharynx, as it passes through the air flowing into the human body from the nasal cavity.
Golosoobrazovatelnaya function of the pharynx is the formation and reproduction of sound produced in the throat. This function depends on the functional and anatomical state of neuromuscular apparatus throat. During the pronunciation of sounds soft palate and tongue, changing its position, closes or opens the nasal passages, allowing the formation of the tone and pitch of the voice.
Pathological changes in voting may occur due to nasal breathing disorders, birth defects of the hard palate, paresis or paralysis of the soft palate. Report nasal breathing often occurs due to an increase in the nasopharyngeal tonsil by its pathological proliferation of lymphoid tissue. Proliferation adenoids increases the pressure within the ear, the sensitivity of the tympanic membrane is significantly reduced. The circulation of air and mucus in the nasal cavity is inhibited that promotes the growth of pathogens.
Pischeprovodnaya function of the pharynx is to form acts of sucking and swallowing. The protective function is performed by pharyngeal lymphoid ring, which together with the spleen, thymus and lymph nodes form a single body's immune system. Furthermore, on the surface of the mucous membrane of the pharynx are many cilia. In case of irritation of the mucous membrane of the pharynx muscles is reduced, its lumen narrowing, and mucus appear pharyngeal gag, cough reflex. Coughing all harmful substances adhering to the cilia are ejected.