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Pharynx

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The pharynx is a vertical hemicylindrical tube made of muscle that joins the larynx with the esophagus. It is a common pathway for the food and air we breathe. We can divide it into three regions: nasopharynx, oropharynx and laryngopharynx.

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What is the pharynx?

The pharynx is a muscular tube located between the cervical spine and the nasal cavity, mouth, and larynx. It is connected at the top with the base of the skull to the C6 cervical vertebra and at the bottom it joins the esophagus. It is divided into three parts: the nasopharynx, oropharynx, and laryngopharynx .

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  • Definition
  • Features of the pharynx
  • What is it for
  • Parts of the pharynx
  • Location
  • Function
  • Muscles
  • Diseases
  • Pharynx care
  • How it differs from the larynx
  • Importance

Definition

The pharynx is a vertical tube made of muscle , measuring 14 to 16 cm in length. It is located in front of the cervical spine and behind the nasal cavity, mouth, and larynx . It joins the larynx with the esophagus and participates in breathing and swallowing .

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Features of the pharynx

  • It is tubular in shape and pinkish in color .
  • The pharynx is divided into three parts: nasopharynx, oropharynx, and
  • It is located between the nasal or oral cavity and the esophagus.
  • It has muscles with circular fibers and with longitudinal fibers .
  • It fulfills functions in the respiratory system , in the digestive system and collaborates with the vocalization and the balance of the air pressure of the middle ear.

What is it for

The pharynx serves to let food and liquids pass into the esophagus when we swallow, it also plays an important role in the respiratory system, allowing air to pass into the larynx. On the other hand, the pharynx assists in speech, since the sounds of vocalization resonate in it.

Parts of the pharynx

Nasopharynx

It is the upper portion of the pharynx, it goes from the choanas to the soft palate.

  • Anterior wall: it continues forward with the nasal cavities through the choanas.
  • Posterior wall: it is related to the first two cervical vertebrae.
  • Upper wall: corresponds to the pharyngeal vault, it is related to the lower face of the sphenoid. At this level we find the pharyngeal pituitary gland and the pharyngeal tonsil.
  • Side walls: right and left. The pharyngeal orifice of the auditory tube and the levator impeller are located here.
  • Lower wall: it is made up of the posterior edge of the hard palate and the upper face of the soft palate, which prevents the exit of food.

Oropharynx or oropharynx

It is the portion of the pharynx that is behind the mouth.

  • Anterior limit: corresponds to the isthmus of the jaws and the root of the tongue.
  • Lateral walls : the lateral walls are two, right and left and are formed by the pharyngolaryngeal canals and by the palatopharyngeal arches. Here are the right and left palatine tonsils, which make up Waldeyer’s lymphatic ring.
  • Posterior wall: it is related to the anterior faces of the first cervical vertebrae.
  • Upper wall: formed by the lower part of the soft palate during swallowing.
  • Lower limit: it continues with the laryngopharynx at the level of the hyoid bone.

Laryngopharynx

It is the third portion of the pharynx, located behind the larynx. It runs from the upper edge of the epiglottis and the pharyngoepiglottic folds to the lower edge of the thyroid cartilage, where it continues with the esophagus.

  • Posterior wall: it is related to the C4, C5 and C6 vertebrae.
  • Lateral walls and posterior wall: they are made up of the middle and lower constrictor muscles.
  • Internal wall: made up of the palatopharyngeal and stylopharyngeal muscles.

Location

The pharynx is located between the larynx and the esophagus. Above is the base of the skull, below the esophagus, in front is the cervical spine and behind the nasal cavity, mouth and larynx.

Function

  • In the digestive system: the pharynx fulfills the second phase of swallowing, receiving food from the mouth and then contracts its muscles to carry the food bolus into the esophagus.
  • In the respiratory system: the pharynx allows air inhaled through the nose or mouth to pass through it to reach the windpipe and then the lungs. In the same way, it allows the exhaled air from the lungs to pass through it to send it to the outside through the nose or through the mouth.
  • Vocalization: the pharynx helps in the process of speech, since the sounds of vocalization resonate in it.
  • Equalizes the air pressure in the middle ear: since the Eustachian tube connects to the middle ear and the pharynx. The tube opening in the nasopharynx opens and closes, equalizing the air pressure in the middle ear with the outside atmosphere.

Muscles

The muscles of the pharynx are divided into two groups: the constrictor muscles that have the fibers oriented in a circular direction and the longitudinal muscles that have the fibers oriented vertically.

Constrictor muscles

They are responsible for narrowing the pharyngeal cavity, from the top to the bottom, to help swallow and move the bolus into the esophagus. All constrictor muscles are innervated by the vagus nerve.

  • Superior constrictor muscle: formed by 4 portions: pterygopharyngeal, oropharyngeal, milopharyngeal, and glossopharyngeal. It is inserted posteriorly into the pharyngeal raphe and anteriorly inserted into the pterygomandibular raphe, adjacent mandible, and pterygoid hook.
  • Median constrictor muscle: it goes from the hyoid bone to the pharyngeal raphe. It has two portions: chondropharyngeal and ceratopharyngeal. It is inserted posteriorly into the pharyngeal raphe and is inserted posteriorly on the superior border of the greater horn of the hyoid bone, on the adjacent borders of the lesser horn, and on the stylohyoid ligament.
  • Inferior constrictor muscle: It has a thyropharyngeal portion, which extends from the oblique line of the thyroid cartilage to the pharyngeal raphe, and a cricopharyngeal portion, which extends from the cricoid cartilage to the pharyngeal raphe.

Longitudinal muscles

They are responsible for elevating the pharyngeal wall during swallowing, raise the pharyngeal wall and move the bolus through the pharynx into the esophagus.

  • Stylopharyngeal muscle: it is innervated by the glossopharyngeal nerve. It originates from the medial aspect of the base of the styloid process and inserts into the pharyngeal wall.
  • Salpingopharyngeal muscle: it is responsible for elevating the pharynx and opening the auditory tube at the time of swallowing. It is innervated by the vagus nerve. It originates from the inferior aspect of the pharyngeal termination of the auditory tube and inserts into the pharyngeal wall.
  • Palatopharyngeal muscle: It originates in the upper part of the palatal aponeurosis and inserts between the levator soft palate muscle and the hook of the pterygoid process. It is innervated by the vagus nerve.

Diseases

  • Pharyngitis
  • Parapharyngeal abscess
  • Paratonsillar abscess
  • Pharyngeal cancer

Pharynx care

To care for the pharynx and avoid its diseases, we must:

  • Avoid smoking.
  • Avoid inhaling irritants.
  • Do not ingest alcoholic beverages.
  • Drink 2 liters of water a day.
  • Maintain good oral hygiene.

How it differs from the larynx

  • The larynx is made up of nine cartilages and the pharynx of circular fiber muscles and longitudinal fiber muscles.
  • The pharynx performs functions in speech, the digestive system, and the respiratory system, unlike the larynx, which only performs functions in the respiratory system and speech.
  • The larynx joins the pharynx with the trachea, while the pharynx joins the oral / nasal cavity with the esophagus.
  • The larynx protects the trachea from swallowing and the pharynx does not.
  • The pharynx balances the pressure of the middle ear and the larynx does not.

Importance

The importance of the pharynx lies in the fact that it is a fundamental structure for breathing, phonation and for swallowing food, since food, liquids and the air we breathe pass through its structure. In addition to being in charge of regulating the air pressure in the middle ear.

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