The pterygomaxillary fissure is a small but important structure in human anatomy, located in the skull near the base of the cranium. It is a narrow channel or groove that separates the pterygoid process of the sphenoid bone from the maxilla, a bone in the upper jaw. This fissure has several important functions and plays a role in several key structures and systems within the body.
Structure
The pterygomaxillary fissure is a small groove or channel that is located at the base of the skull, between the pterygoid process of the sphenoid bone and the maxilla. The pterygoid process is a bony projection that extends laterally from the sphenoid bone, and is located just behind the socket of the eye. The maxilla is a bone in the upper jaw that forms the lower part of the orbit, or eye socket.
It is a thin, elongated structure that is oriented vertically within the skull. It is approximately 2-3 centimeters in length and is bordered by the pterygoid process and the maxilla on either side. The fissure is relatively narrow, with a width of only a few millimeters.
Location
It is located at the base of the skull, in the region known as the pterygopalatine fossa. This fossa is a shallow, triangular-shaped depression that is located between the pterygoid process of the sphenoid bone and the maxilla. The pterygopalatine fossa is located just behind the socket of the eye and is bounded by the lateral and medial pterygoid plates.
It is situated within the pterygopalatine fossa, and is located posterior to the infraorbital foramen, which is a small hole in the skull that allows the infraorbital nerve and blood vessels to pass through. The infraorbital foramen is located in the maxilla, just below the orbit.
Function
One of the primary functions of the fissure is to allow the passage of several important structures through the pterygopalatine fossa. These structures include the maxillary artery, the pterygoid venous plexus, and the maxillary nerve.
The maxillary artery is a major blood vessel that supplies blood to the head and neck region. It branches off from the external carotid artery and passes through the pterygomaxillary fissure on its way to the orbit and other structures in the head and neck.
The pterygoid venous plexus is a network of veins that is located in the pterygopalatine fossa. These veins are responsible for draining blood from the head and neck region and returning it to the heart.
The maxillary nerve is a major nerve that is responsible for providing sensory innervation to the face, including the upper and lower jaws, the teeth, the gums, and the mucous membranes of the nose and mouth. The maxillary nerve passes through the pterygomaxillary fissure on its way to the orbit and other structures in the head and neck.
In addition to allowing the passage of these structures, the pterygomaxillary fissure also plays a role in the movement of the jaw. The pterygoid muscles, which are located within the pterygopalatine fossa, are responsible for moving the jaw from side to side and up and down. The pterygoid muscles are connected to the pterygoid process and the maxilla, and the pterygomaxillary fissure allows for the movement of these muscles as they function to move the jaw.
Finally, the pterygomaxillary fissure also plays a role in the drainage of sinuses. The pterygopalatine fossa contains the maxillary sinus, which is one of the paranasal sinuses located within the skull. The maxillary sinus is responsible for producing mucus, which helps to moisten and humidify the air that we breathe. The pterygomaxillary fissure allows for the drainage of the maxillary sinus, allowing the mucus to be expelled from the sinus and into the nasal cavity.
