Pterygoid processes of the sphenoid
Encyclopedia
The pterygoid processes of the sphenoid, one on either side, descend perpendicularly from the regions where the body and great wings unite.
Each process consists of a medial pterygoid plate
and a lateral pterygoid plate
, the upper parts of which are fused anteriorly; a vertical sulcus, the pterygopalatine groove, descends on the front of the line of fusion.
The plates are separated below by an angular cleft, the pterygoid fissure (or pterygoid notch), the margins of which are rough for articulation with the pyramidal process of the palatine bone
.
The two plates diverge behind and enclose between them a V-shaped fossa, the pterygoid fossa, which contains pterygoideus internus and tensor veli palatini.
Above this fossa is a small, oval, shallow depression, the scaphoid fossa, which gives origin to the tensor veli palatini.
The anterior surface of the pterygoid process is broad and triangular near its root, where it forms the posterior wall of the pterygopalatine fossa
and presents the anterior orifice of the pterygoid canal
.
In many mammals it remains as a separate bone called the pterygoid bone.
Its name is Greek for "resembling a fin or wing", from its shape.
Each process consists of a medial pterygoid plate
Medial pterygoid plate
The medial pterygoid plate of the sphenoid is narrower and longer than the lateral pterygoid plate; it curves lateralward at its lower extremity into a hook-like process, the pterygoid hamulus, around which the tendon of the Tensor veli palatini glides.The lateral surface of this plate forms part...
and a lateral pterygoid plate
Lateral pterygoid plate
The lateral pterygoid plate of the sphenoid is broad, thin, and everted; its lateral surface forms part of the medial wall of the infratemporal fossa, and gives attachment to the lateral pterygoid muscle; its medial surface forms part of the pterygoid fossa, and gives attachment to the medial...
, the upper parts of which are fused anteriorly; a vertical sulcus, the pterygopalatine groove, descends on the front of the line of fusion.
The plates are separated below by an angular cleft, the pterygoid fissure (or pterygoid notch), the margins of which are rough for articulation with the pyramidal process of the palatine bone
Palatine bone
The palatine bone is a bone in many species of the animal kingdom, commonly termed the palatum .-Human anatomy:...
.
The two plates diverge behind and enclose between them a V-shaped fossa, the pterygoid fossa, which contains pterygoideus internus and tensor veli palatini.
Above this fossa is a small, oval, shallow depression, the scaphoid fossa, which gives origin to the tensor veli palatini.
The anterior surface of the pterygoid process is broad and triangular near its root, where it forms the posterior wall of the pterygopalatine fossa
Pterygopalatine fossa
The pterygopalatine fossa is a fossa in the skull. It is the indented area medial to the pterygomaxillary fissure leading into the sphenopalatine foramen.-Boundaries:It has the following boundaries:...
and presents the anterior orifice of the pterygoid canal
Pterygoid canal
The pterygoid canal is a passage in the skull leading from just anterior to the foramen lacerum in the middle cranial fossa to the pterygopalatine fossa.-Structure:...
.
In many mammals it remains as a separate bone called the pterygoid bone.
Its name is Greek for "resembling a fin or wing", from its shape.