Pharynx Definition

The pharynx is a five-inch long tube that starts near our nose and ends at our windpipe. The pharynx is generally considered a part of the throat in both vertebrate and invertebrate animals. In humans, it is a hollow structure (or muscular cavity) lined with moist tissue. This is typical of all structures within our alimentary and digestive tracts. Having a moist lining with a mucus rich barrier allows us both to breathe and for our food to travel safely through our canal without damaging our sensitive tissues. The muscular pharynx effectively forms the entry for the esophagus, or our “food canal,” and the trachea, also known as our “windpipe.” For this reason, the pharynx is considered a part of both our respiratory and digestive systems.

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The image above illustrates the human pharynx and its surrounding structures.

Pharynx Location

As we will discuss in more detail below, the pharynx is comprised of three sections. The pharynx’s location can be said to start in the space immediately behind our nasal cavity, and ends just above our esophagus and larynx – which are the two main passageways that follow entry at the mouth for food and air, respectively.

Parts of the Pharynx

The pharynx measures about thirteen centimeters long and is made up of several sections. The uppermost portion of the pharynx is called the “nasopharynx,” which makes sense given its proximity to our nasal cavity. As such, it is the space where air is able to move its way through the nose and eventually into our respiratory linings, again demonstrating the pharynx’s role in our respiration. This area is called the conduction zone as it filters, warms, and injects the inhaled air with moisture so that it is able to pass into our lungs successfully. If we were to visualize the nasopharynx physically, its uppermost portion lies between the base of our skull to our soft palate and ends near our tonsils.

In the same vein, the “oropharynx” is the “oral” section of the pharynx. It is thus found in the region near our mouth, staring at our soft palate and ending at the epiglottis – which is the high-rising “flap-like” tissue found posterior to our tongue.

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Finally, we have our laryngopharynx. This section lies between our epiglottis and ends at our esophagus. Our esophagus, of course, is a continuation of the passageway that moves food to our gut through peristalsis, or muscular pulsing.