Pharynx Function: What is it? Structure, Functions, Arterial Supply and Clinical Conditions

It is located in the back of the throat, where it exists as a muscular cavity that is approximately 5 inches (12.7 cm) long.

Structure

The entry point for nutrition is the nasopharynx. The pharynx is basically the junction of the nose and mouth. There are three parts of the pharynx called the nasopharynx, oropharynx, and hypopharynx, depending on their location along the cavity.

The midsection of the nasopharynx is located between the soft palate and the hyoid bone region . This middle region is known as the oropharynx.

The anterior wall of the oropharynx is created by the base of the tongue. Along the posterior lateral wall are the palatine tonsils, and along the base of the tongue are the lingual tonsils.

Located directly behind the nasal cavity and just above the soft palate, this is the highest point in the pharynx.

The uvula, which is the pendulum-like attachment that sits over the opening of the esophagus, hangs from the lower middle segment of the soft palate.

The inner walls of the pharynx are covered with a mucous layer that serves to help food pass through during the digestive process .

The Eustachian tubes, which are the vital auditory tubes, join the tympanic cavities with the nasopharynx.

Adenoids, which are also known as pharyngeal tonsils, are located in the nasal cavity along the back wall.

When swallowed, the uvula and soft palate lift up to prevent food from mistakenly entering the nasal cavity.

As the uvula and soft palate enlarge, they create a blockage along the way, forcing food down the esophagus.

The sudden expulsion of air when swallowing fluid from the uvula once again creates a blockage along the way, preventing the fluid from entering the nasopharynx and forcing the fluid out of the nasal cavity.

The lowest region of the pharynx can be found from the region of the hyoid bone to the esophagus and larynx.

This section is known as the laryngopharynx. The digestive system and the respiratory system obviously become two separate systems in the lower region of the laryngopharynx.

Here, the food and liquid that has been swallowed is directed to the esophagus and the air that has been inhaled is directed to the anterior larynx.

Features

The pharynx in the digestive system plays an important role. This muscular structure passes food and liquids from the mouth into the esophagus during swallowing .

The unique construction and location of the pharynx allows it to perform this role in digestion and at the same time function as part of the respiratory system.

Vocalization sounds also resonate throughout the pharynx, creating additional responsibility for speech assistance.

The pharynx is segregated into three basic regions, based primarily on the function it performs and the area it serves.

The swallowing mechanism is controlled by a swallowing center in the medulla oblongata and the pons.

It is initiated by touch receptors in the pharynx as a food bolus that reaches the back of the throat.

The soft palate is stretched upward, to stop food from entering the nasal cavity, and some palatopharyngeal folds are closed, so that only a small bolus can pass (preventing posterior blockage).

The larynx is pulled up towards the epiglottis, which passively shuts off its entrance, and the vocal cords are brought closer together, narrowing the passage between them.

The respiratory center of the medulla is directly inhibited by the swallowing center, while swallowing occurs – swallowing apnea (swallowing stopping inhalation).

The upper esophageal sphincter relaxes to let food through, and then a sequence of striated constrictor muscles in the pharynx does some peristalsis.

Arterial and venous supply

The arteries

Superiors
  1. Ascending pharynx.
  2. Branches of lingual, facial (tonsillar, palatine ascending), maxilla.
Lower
  1. Pharyngeal branches of the inferior thyroid artery.

Veins

They form a plexus that drains into the pterygoid plexus. Inferiorly in facial veins and VYI.

Nervous fountain

The inversion is of a sensitive type.

  • The nasopharynx: pharyngeal branch of the maxillary nerve.
  • La oropharynx: glosopharyngeal nerve.
  • The laryngopharynx: vagus nerve.

Lymph

The lymphatic vessels drain directly into the deep cervical lymph nodes or indirectly into the retropharyngeal or paratracheal nodes.

Clinical conditions

Occasionally, there are problems with the pharynx that are often found after symptoms such as pain, swelling or inflammation, itching, and difficulty swallowing develop.

A doctor should be seen for a definitive diagnosis so that appropriate treatment can begin when a problem with the pharynx is suspected.

Among the most common diseases of the pharynx we have:

  • Pharyngeal cancer: it is a malignant neoplasm of the throat.
  • Nasopharyngeal carcinoma: is cancer of the nasopharynx.
  • Pharyngitis .
  • Dysphagia .
  • Paresthesias of the pharynx.
  • Diphtheria.