The hypoglossal canal is a small bony channel located in the base of the skull. It is an important structure in human anatomy as it allows for the passage of the hypoglossal nerve, which is responsible for controlling the muscles of the tongue.
Structure
The hypoglossal canal is a small, oval-shaped bony channel located in the base of the skull. It is formed by the joining of several bones in the skull, including the occipital bone, the sphenoid bone, and the temporal bone. The hypoglossal canal is located just posterior (behind) to the foramen magnum, which is the large opening at the base of the skull through which the spinal cord passes.
It is lined with a thin layer of connective tissue called the dura mater. This tissue helps to protect the hypoglossal nerve as it passes through the canal. The hypoglossal canal is also surrounded by several muscles and blood vessels, including the internal carotid artery and the vertebral artery.
Location
As mentioned above, the hypoglossal canal is located in the base of the skull. More specifically, it is located just posterior to the foramen magnum and just anterior (in front of) to the occipital condyles. The occipital condyles are bony protuberances located on either side of the foramen magnum that allow for the movement of the head.
Function
The primary function of the hypoglossal canal is to allow for the passage of the hypoglossal nerve. The hypoglossal nerve is the twelfth cranial nerve and is responsible for controlling the muscles of the tongue. These muscles allow us to move our tongue in different directions, as well as to stick our tongue out, swallow, and speak.
The hypoglossal nerve emerges from the brainstem and passes through the hypoglossal canal on its way to the tongue. It then branches out and innervates several different muscles of the tongue, including the genioglossus, the hyoglossus, and the styloglossus. These muscles work together to control the movement and position of the tongue.
Clinical Significance
There are several conditions that can affect the hypoglossal canal and the hypoglossal nerve. One such condition is a hypoglossal nerve injury, which can result from trauma to the head or neck, surgery, or other underlying medical conditions. A hypoglossal nerve injury can cause weakness or paralysis of the tongue, difficulty speaking or swallowing, and difficulty controlling the movement of the tongue.
Another condition that can affect the hypoglossal canal is a hypoglossal canal stenosis. This is a condition in which the hypoglossal canal becomes narrowed or constricted, which can cause compression of the hypoglossal nerve. A hypoglossal canal stenosis can also cause weakness or paralysis of the tongue, as well as other symptoms such as difficulty swallowing or speaking.
In addition to these conditions, the hypoglossal canal and hypoglossal nerve can also be affected by certain medical procedures. For example, during a spinal fusion surgery, the hypoglossal nerve may be temporarily at risk of injury due to its close proximity to the surgical site.
