Throat

Throat – the cylindrical, slightly squeezed in the sagittal direction funneled muscular tube from 12 to 14 cm long placed ahead of cervical vertebrae. The vault of the farynx (an upper wall) connects to a base of skull, a back part fastens to an occipital bone, side parts – to temporal bones, and the lower part passes into a gullet at the level of the sixth vertebra of a neck.

Throat – the place of decussation of respiratory and digestive ways. Food weight from an oral cavity during process of swallowing comes to a throat, and then to a gullet. Air from a nasal cavity through a postnaris or from an oral cavity through a pharynx also comes to a throat, and further to a throat.

Throat structure

In an anatomic structure of a throat allocate three main parts – a nasopharynx (an upper part), a stomatopharynx (middle part) and a laryngopharynx (lower part). The stomatopharynx and a nasopharynx connect to an oral cavity, and the laryngopharynx is connected with a throat. The throat connects to an oral cavity by means of a pharynx, with a nasal cavity it is reported through a postnaris.

Stomatopharynx – continuation of a nasopharynx. A soft palate, palatal handles and a back of the tongue separate a stomatopharynx from an oral cavity. The soft palate falls directly to a pharyngeal cavity. During swallowing and pronouncing sounds the sky rises up, thereby providing articulateness of the speech and preventing hit of food in a nasopharynx.

The laryngopharynx begins in the fourth or fifth vertebra and, smoothly going down, passes into a gullet. The front surface of a laryngopharynx is presented to that by area where the lingual almond is located. Getting into an oral cavity, food is made small, further the food lump comes through a laryngopharynx to a gullet.

On sidewalls of a throat funneled openings of acoustical (eustachian) pipes are located. The similar structure of a throat promotes an equilibration of atmospheric pressure in a drum cavity of an ear. Around these openings pipe almonds in the form of pair accumulations of an adenoid tissue are placed. Similar accumulations are available also in other parts of a throat. Lingual, pharyngeal (adenoid), two pipe, two palatine tonsils create a lymphoid ring (Pirogov's ring – Valdeyera). The lymphoid ring interferes with penetration into a human body of alien substances or microbes.

The wall of a throat consists of a muscular layer, an extima and a mucous membrane. The muscular layer of a throat is presented by group of muscles: the shiloglotochny muscle raising a throat and a throat and any pair cross-striped muscles – upper, average and lower the szhimatel of a throat narrowing its gleam. When swallowing by efforts of longitudinal muscles of a drink rises, and cross-striped muscles, being consistently reduced, push a food lump.

Between a mucous and muscular coat the submucosa with fibrous fabric is located.

The mucous membrane in the different locations is various on the structure. In a laryngopharynx and a stomatopharynx mucous is covered with a multilayer flat epithelium, and in a nasopharynx – a ciliate epithelium.

Functions of a throat

The throat takes part in several vital functions of an organism at once: meal, breath, phonation, protective mechanisms.

All departments of a throat as through it there passes the air coming to a human body from a nasal cavity participate in respiratory function.

Golosoobrazovatelny function of a throat consists in formation and reproduction of the sounds which are formed in a throat. This function depends on a functional and anatomic condition of the neuromuscular device of a throat. During a pronunciation of sounds a soft palate and language, changing the situation, close or open a nasopharynx, providing formation of a timbre and height of a voice.

Pathological changes of a voice can arise because of disturbance of nasal breath, inborn defects of a hard palate, paresis or paralyzes of a soft palate. Disturbance of nasal breath most often is caused by pathological growth of its adenoid tissue because of increase in a nasopharyngeal almond. Growth of adenoides leads to increase in pressure in an ear, at the same time sensitivity of a tympanic membrane considerably decreases. Circulation of slime and air in a nasal cavity is slowed down that promotes reproduction of causative organisms.

Pishcheprovodny function of a throat consists in formation of acts of suction and swallowing. Protective function is performed by a lymphoid ring of a throat which together with a spleen, a thymus and lymph nodes forms uniform immune system of an organism. Besides, on a mucosal surface of a cover of a throat the set of cilia is located. At irritation of a mucous membrane muscles of a throat are reduced, its gleam is narrowed, slime is emitted and appears pharyngeal emetic кашлевый a reflex. With cough all harmful substances which stuck to cilia are removed outside.