What Is the Hyoid Bone and Its Function?

Skeleton highlighting the hyoid bone and larynx.
Skeleton highlighting the hyoid bone and larynx.. maya2008

The little talked about hyoid bone is a unique part of the human skeleton - for a number of reasons. First, it's mobile.  This means that other than its attachment site to the thyroid cartilage (part of the larynx, and discussed below,) it floats.  You can even move your hyoid from side to side - for safety's sake, very gently, please -  by lightly touching either end, and then alternating an ever so slight pushing action that moves the bone from side to side.

(This is called palpating the hyoid bone.)

Second, the hyoid bone plays roles in a number of key functions that keep you alive - from breathing and sleep to using your tongue, and more.  

In this article, we'll explore this small neck bone in terms of function, location, and relationship to other structures.

Location of the Hyoid Bone

The hyoid is situated at the front (anterior) part of the neck between the jaw bone and the thyroid cartilage. (The hyoid bone is firmly secured to the thyroid cartilage by ligaments.)  It resides at the level of the 3rd cervical vertebra, and attaches, by means of tendons to muscles of tongue, the floor of the mouth and the anterior neck.

Although it is small, the hyoid bone is only rarely fractured - this is due to its location which generally protects the bone from all but direct trauma.

The hyoid bone is located above the Adam's apple and below the tonsils and the epiglottis.

 While not technically a part of the larnyx, it resides very close (on top.)  It even provides an attachment site for muscles that control movements of the larynx.   

In case you forgot, the larynx is the area above your windpipe (trachea) that helps protect you from choking on foreign objects.  Perhaps the most well known example of this is when food "goes down the wrong pipe."   The larynx does its primary job of protecting you from choking by quickly closing off the opening to the trachea when a foreign object tries to enter.

(Remember, the windpipe is build for air, not things.)  

Another thing the larynx does - and something we're all pretty familiar with - is to produce sound; among non-medical people, larynx is also known as the voice box.  

And finally, the larnyx is responsible for coughing (part of the choking protection mechanism function mentioned above.) The larnyx has a few other purposes, as well, including playing a role in ventilation and functioning as a sensory organ.

Hyoid Bone Function

But we're here to talk about the functions of the hyoid bone, so let's have at it.

First, it provides a place of attachment for several anterior (front) neck muscles.  The muscles that attach onto the hyoid bone include, but are not limited to, the sternohyoid, mylohyoid, omohyoid, digastric muscles. These and other anterior neck muscles play a role in swallowing and may be affected in cases of neck injuries or misalignment.

A second function of the hyoid bone is to provide a foundation or base from which the tongue can move.

 

And, finally, the hyoid bone is involved in respiration.  This is because it plays a role in keeping the airway open - particularly relevant to sleep and sleeping disorders such as sleep apnea.

Source:

Moore, K., Dalley, A. Clinically Oriented Anatomy. Fifth. Edition. Lippincott, Williams & Wilkins. 2006. Baltimore.

Porr, J., D.C., et. al. Traumatic hyoid bone fracture - a case report and review of the literature.  J Can Chiropr Assoc. Dec 2012. Accessed Aug 2016. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3501913/

 

Continue Reading