Pharynx - is part of the digestive and respiratory systems, which has a funnel shape in the form of a hollow tube and muscle located behind the larynx, and nasal and oral cavities, the front of the cervical spine. This body carries out important functions related to breathing, eating, sound-shaping and protecting the body from infectious agents.
Anatomical features
human anatomy pharynx is arranged in a special way in order to perform the functions of respiration and digestion. It is in this department there is the intersection of these ways, but its structure allows food to enter only into the esophagus, and the air - in the respiratory system.
The structure of the nasopharynx is arranged in such a way that at the time of the airways open swallowing movements, but at the time of movement of food bolus through the esophagus, they are blocked by the muscles of the larynx. These mechanisms prevent the penetration of food in the breathing hole.
Throat is considered as the entrance gate for a variety of microorganisms, including pathogens. Due to the fact that its inner surface comprises a cluster of lymphoid tissue, which is component of the immune system, there occurs the capture and neutralization of pathogenic microflora.
Location of the pharynx in relation to other organs:
- in front - with a compound of the larynx and the transition into the mouth, bypassing the shed;
- at the top - a message through choanae (breathing passages) with the inner nasal cavity;
- on each side - the connection to the middle ear through the eustachian channel;
- bottom - moves into the esophagus.
STRUCTURE SIPS HUMAN
When considering the anatomical features of the pharynx release its 3 main sections.
The main departments:
- Nasopharynx, nose or upper section. Located above the sky level with the first and second vertebra of the neck and its connection with the nasal cavity occurs through choanae. With the openings of the Eustachian tubes, arranged at the lower nasal passage into the throat, there is a relationship with the internal cavity of the ear drum. This anatomical feature allows you to equalize the pressure in both cavities and to ventilate the latter. For this reason, nasal breathing is not only important for the respiratory system, but also for auditory function. Between the soft palate and the outlet passage disposed Eustachian concentration of lymphoid tissue in the form of the tonsils. They are represented by pairs of palatine and pipe, as well as adenoid and lingual tonsil. Their accumulation forms peculiar lymphatic ring which ring Pirogov-called Heinrich Wilhelm Gottfried von Waldeyer-Hartz. Proliferation or hypertrophy pharyngeal tonsils, may block or estuaries choanal auditory pipes, which causes the symptoms of shortness of breath, and violation of the Eustachian passage function in children under the age of 14 years. In a more adult pharyngeal tonsil atrophy, and this problem can not occur. The boundary between the upper and middle conditional division, separation occurs during line back on the hard palate.
- Oropharynx - oral or middle part. It includes a portion of the sky to the larynx. A compound with the oral cavity occurs through the throat. Top jaws shut heaven and tongue, below its limit root of the tongue. On either side of the pharynx are palatal arch. Oropharynx formed rear and two side walls. Here is the intersection of the respiratory and digestive tract. The structure of the pharynx in this area has features that allow lifted soft palate during swallowing and pronouncing the sounds. Thus, there is insulation nasopharynx when making these actions. Pharyngeal wall can be examined widely open the mouth.
- Hypopharynx - guttural, or the lower part. The narrow passage located behind the larynx. There was isolated the front, rear and two side walls. Being at rest, the front and rear walls are locked to each other. The front wall forms a protrusion, which is located above the entrance to the larynx.
The esophagus has a funnel shape, flattened in the anteroposterior direction, the wide end of which originates at the base of the skull, more reaches 6-7 neck vertebrae, the esophagus narrows and continues. The average body length of about 12-14 cm, its inner space is formed pharyngeal cavity. The middle and upper parts are united with the oral cavity, and the bottom connects with the larynx.
The wall of the organ consists of muscle, connective tissue and mucous membranes. The latter is represented multicore ciliated epithelium in its bow, and is a continuation of membranes of the mouth and nose. The coating layer other surfaces lined by stratified squamous epithelium neorogovevayuschy which firmly fused with the muscle layer. Between the muscle layer and mucous submucous layer is represented by fibrous tissue. The inclusion of the connective tissue can be found in the buccal muscle and tissue of the esophagus.
The muscles of the pharynx:
- shiloglotochnaya - controlled by consciousness, raises the larynx and pharynx;
- detrusor muscle (upper, middle, lower) - narrows the lumen of the pharynx.
One at work these muscle groups helps the passage of food down the esophagus toward.
swallowing
The special structure and function of the throat allow it to carry out swallowing. swallowing reflex process occurs by tension and relaxation of different muscle groups.
The process of swallowing:
- In the mouth, the food is mixed with saliva and carefully crushed. It is formed from a homogeneous ball, which then falls on the area of the tongue.
- At the root of the tongue is a group of sensitive receptors whose stimulation triggers muscle contraction, making the sky rises. At the same moment a message is blocked throat with the nasal cavity and the food does not penetrate into the airways.
- bolus of food is pushed through language in the throat. Here muscles displace the hyoid bone, which causes the elevation of the larynx and the epiglottis closes the airways.
- In the pharynx by means of alternate reduction of various muscle groups is provided by the gradual passage of food towards the esophagus.
FEATURES SIPS
Throat performs functions related to the life-support of the body and its protection.
Main functions:
- Esophageal - provides swallowing and sucking movements due to the contractile muscle. This process is an undoubted reflex act.
- Respiration is provided by all of the organ, as air flows through them from the nose and mouth in the lower respiratory tract. This process is made possible by the connection of the pharynx, larynx, pharynx and choanae.
- Phonation is the creation and playback of sounds, the formation of which is provided in the larynx the vocal cords. When pronouncing the sounds of the language and soft palate is closed and opened the entrance to the nasal passages, and this is provided by the timbre and pitch of the index. person sip advocates a kind of cavity due to its ability to contraction and expansion.
- Protective - lymphoid ring together with other organs of immunity protects the organism against pathogens. tonsil surface is covered with furrows - lacunae on whose surface takes place defusing infection. Additionally, during stimulation of ciliary epithelium to the mucosal surface, there is muscle contraction, pharyngeal lumen narrows, stands out mucus and coughing begins, which acts as a protective reaction body.
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