Description of the Anatomy of the Pharynx

Today's article is about the anatomy of the pharynx. You may already know that the pharynx is an organ that's responsible for important functions such as helping to control breathing and swallowing. Continue reading to find out more about it.

Reviewed and approved by the pharmacist María Vijande.

Written by María Vijande

Last update: 27 May, 2022

The anatomy of the pharynx is quite simple really. However, we’ll need to tell you a few things about this organ before we get deeper into the subject. For one, it’s a muscular conduit located in front of the spine and behind the nostrils, the oral cavity, and the larynx. It’s also uneven and symmetrical.

In addition, the larynx is approximately 5 1/2 inches long in men and 5 1/8 in women. Its transverse diameter ranges from 1 ³⁷/₆₄ inch to no more than ²⁵/₃₂ at the lower end — we mention the lower end because the pharynx is shaped like a funnel.

This duct extends from the base of the skull to the lower edge of the sixth cervical vertebra, continuing downward along with the esophagus. Topographically, it divides into three regions: the rhino pharynx, oropharynx, and laryngopharynx. We’ll describe them in more detail in this article.

Pharyngeal anatomy and functions

According to a study published in the fifth edition of Physiology of the Gastrointestinal Tract, this organ is responsible for four main functions.

1. It helps digest food by contracting its walls and the swallowing reflex it sends into the esophagus
2. Also, it’s involved in breathing, so any air taken in through the mouth and nose goes into the trachea and from there to the lungs
3. It helps vocalize
4. It balances the air pressure in the middle ear by properly making the sound conduction

The anatomy of the pharynx – the rhino pharynx

The rhino pharynx is the only aerial part of this organ. What we mean here is that it’s the only structure of the pharynx anatomy that’s permeable and continuously open to the air. It’s in front of the cervical rachis and below the base of the skull, also known as the nasopharynx.

Furthermore, it communicates downwards with other parts of the pharynx anatomy – such as the oropharynx and the laryngopharynx. The rhino pharynx connects with four parts:

• Firstly, the anterior wall of the rhino pharynx is delimited by the posterior and inferior portion of the nasal septum and communicates to the nasal cavities through the choanae.
• The mucosa of the posterior wall contains the opening of the Eustachian tube communicating the rhino pharynx with the middle ear.
• The skull marks the upper limit through the skin of the sphenoid bone (The upper wall of this structure of the pharynx anatomy contains the adenoids in children under 12 years of age. These are a patch of tissue that are part of the lymphatic system of the body).
• Finally, the inferior limit forms by the posterior and inferior glossopharyngeal nerve of the palatine bones.

The anatomy of the pharynx – the oropharynx

Functionally, this is the most complex pharyngeal subdivision. This is because the soft palate separates the rhino pharynx from this structure as it’s in charge of regulating the passage of air and food through the pharynx. Thus, it:

• Limits pharyngeal-nasal reflux
• Propels the alimentary bolus
• Facilitates air passage
• And, finally, participates in vocalization

The palate, posterior, spine, and prevertebral muscles comprise its upper limit. Also, there’s an imaginary plane that passes through the upper edge of the epiglottis underneath.

The epiglottis is an organ in the form of a cartilaginous lamina that closes the upper opening of the larynx when you swallow.

As for the lateral limits, the tonsil fossae and the fauces delimit the continuity with the oral cavity. One can say the anatomy of the oropharynx is seemingly simple; however, it’s complex deep inside.

The anatomy of the pharynx – laryngopharynx

This part corresponds to the lower portion of the pharynx, known as the hypopharynx. Furthermore, it extends from the upper edge of the epiglottis to the lower edge of the cricoid cartilage.

It connects to the larynx at the front and there are two vertical depressions known as pyriform sinuses on both sides. The alimentary bolus descends towards the esophagus through these sinuses.

Summarizing

The anatomy of the pharynx is relatively simple, although it’s an organ with important functions. It divides into three portions: the rhino pharynx, oropharynx, and laryngopharynx. All of them together are determinant for important processes such as vocalization, breathing, and the propulsion of the bolus when eating.