What is the only jointless bone in the human body?

Do you know what the only jointless bone in the human body is? It's called the hyoid bone, located in the throat.

This small, cone-shaped bone helps to support the tongue and acts as a connector between the skull and spine. Let's take a closer look at this unique bone!

What is the hyoid bone?

The hyoid bone is a small, U-shaped bone located in the neck, just above Adam's apple. It is not attached to other bones and is suspended in the neck by several muscles and ligaments.

The hyoid bone plays an essential role in speech and swallowing, as it provides a point of attachment for the muscles of the tongue, the pharynx, and the larynx.

It also helps to hold the larynx in place and to prevent it from collapsing during swallowing. The hyoid bone is sometimes referred to as the "floating bone" because it is not connected to other bones in the body.

Where is the hyoid bone located?

The hyoid bone is located in the neck, below the chin, and behind the tongue. It is an essential part of the human skeletal anatomy that serves a vital role in speech production, swallowing, and other throat-related activities.

This small, U-shaped bone comprises two symmetrical parts called the body and two horns connected by a central arch.

It is one of only a few bones in the body that does not contact other bones. Instead, it is suspended from several muscles and ligaments that attach it to other structures, such as the mandible, styloid process of the temporal bone, thyroid cartilage, and cervical vertebrae.

What are the functions of the hyoid bone?

The hyoid bone is a crucial component of the human anatomy, located at the base of the tongue in the neck. It is a unique, U-shaped bone made entirely out of cartilage and serves several essential functions related to the throat and speech. 

Tongue support

The essential function of the hyoid bone is to support the tongue. By providing a solid anchor point for muscles, ligaments, and other soft tissue structures in the throat, it maintains a static position for the tongue, allowing it to produce speech properly.

These attachments also give stability and control over tongue movements; for instance, during swallowing, specific muscles connected to the hyoid bone help keep food from entering the airways. 

Speech production and swallowing

In addition to its role in speech production and swallowing, the hyoid bone provides attachment points for some of the muscles involved in holding our heads and supporting our respiratory system.

Protecting vital organs

It also helps protect vital organs such as our larynx by acting as a shield against potential impacts or injuries. Finally, this unique bone may play an important role in vocal expression since its movement affects pitch and volume. 

Despite its small size (one of only three single-piece bones in our bodies), it's clear that the proper functioning of our hyoid bone is essential for many aspects of life - both physical and mental health depends on it.

Without this specialized structure, individuals would be unable to speak correctly or swallow safely; thus, we must maintain good posture habits to keep our hyoid aligned!

What are the ligaments and muscles associated with the hyoid bone?

The muscles associated with the hyoid bone are the geniohyoid muscle that runs from the chin bone upwards towards the Hyoid Bone.

Mylohyoid Muscle runs downwards from the lower jaw (mandible ) to Hyoiod Bone; Stylhoiydd Muscle runs between Hyoiod Bone and Ear Bone (Styloeid Process); Sternothyroid Muscle runs downwards from the throat area(thyroid cartilage) towards HyoiodBone.

All these muscles and their respective ligaments aid in stabilizingHyioodBone while aiding speech production, swallowing, and tongue movements.

How does the hyoid bone move?

The hyoid bone is unique because it's the only bone in the human body that does not attach to any other bone. Instead, it is suspended by various muscles and ligaments, allowing it to move in several directions.

The most important movement of the hyoid bone involves the larynx, which enables us to swallow and speak. By contracting the muscles surrounding this U-shaped bone, we can elevate or depress the hyoid and larynx, resulting in different vocalizations.

That also helps us swallow more efficiently and keep food from entering our windpipes.

The hyoid bone can also move laterally (side-to-side) due to attachments from four paired muscles on both sides of the neck: the geniohyoid muscle and thyrohyoid muscle from above, and the sternohyoid muscle and omohyoid muscle from below.

Together, these muscles help us form sounds like "F" or "V," which require precise control over tongue placement during speech production.

They also stabilize our heads when we perform certain head/neck motions, such as nodding or shaking.

When swallowing becomes difficult or painful due to injury or a medical condition such as ankylosing spondylitis or Parkinson's disease, the hyoid can be manually moved using specially designed therapy tools to position the larynx and facilitate easier swallowing of food correctly.

That is possible because all of its connecting tissues are under voluntary control—unlike other bones in our body that are firmly in place with ligaments and tendons—making it highly mobile even at rest.

What are some common disorders of the hyoid bone?

Among the most common disorders of the hyoid bone are fractures, dislocations, and subluxation.

Fractures

Fractures of the hyoid bone typically occur due to direct trauma to the area, such as being hit in the throat with a blunt object or falling onto one's chin during a sporting event.

In some instances, it can also be caused by indirect trauma when an individual experiences hyperflexion or hyperextension of the neck.

The most common symptom of a fracture is pain in the throat and neck region. Still, if there is any displacement of bone fragments, then other symptoms may include dysphagia (difficulty swallowing), dyspnea (shortness of breath), or dysphonia (hoarseness).

Dislocation and subluxation

Dislocation and subluxation refer to the displacement of the hyoid bone from its normal anatomic position within the anterior neck. These injuries can also be caused by direct trauma to the neck or applying pressure from outside forces; however, they often occur secondary to muscle spasms.

Common symptoms include difficulty swallowing and speaking due to impairment of laryngeal muscle function.

Furthermore, there can be further complications, including chronic pain in the throat and neck regions and limited range of motion.

Depending on the severity, treatment usually involves immobilization with a collar-like device followed by physical therapy for restoring increased mobility post-injury.

Final words

Understanding the movements and disorders of the hyoid bone is essential for comprehensively evaluating any neck or throat-related injury.

This U-shaped bone is unique among all other bones because it has no joint connection to any other bone and is suspended by various muscles and ligaments, allowing it to move in several directions.

Though typically robust, the hyoid bone can still suffer from fractures, dislocations, or subluxations that require proper medical attention.

Finally, what is the only jointless bone in the human body? The answer is the hyoid bone.

DISCLAIMER: buildyourbody.org does not provide medical advice, examination, or diagnosis.

Medically reviewed and approved by Nataniel Josue M D.