Medial pterygoid plate

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Medial pterygoid plate
Sphenoid bone. Anterior and inferior surfaces.
Gray's subject #35 151

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 of the pterygoid fossa, the medial surface constitutes the lateral boundary of the choana or posterior aperture of the corresponding nasal cavity.

Superiorly the medial plate is prolonged on to the under surface of the body as a thin lamina, named the vaginal process, which articulates in front with the sphenoidal process of the palatine and behind this with the ala of the vomer.

The angular prominence between the posterior margin of the vaginal process and the medial border of the scaphoid fossa is named the pterygoid tubercle, and immediately above this is the posterior opening of the pterygoid canal.

On the under surface of the vaginal process is a furrow, which is converted into a canal by the sphenoidal process of the palatine bone, for the transmission of the pharyngeal branch of the internal maxillary artery and the pharyngeal nerve from the sphenopalatine ganglion.

The pharyngeal aponeurosis is attached to the entire length of the posterior edge of the medial plate, and the Constrictor pharyngis superior takes origin from its lower third.

Projecting backward from near the middle of the posterior edge of this plate is an angular process, the processus tubarius, which supports the pharyngeal end of the auditory tube.

The anterior margin of the plate articulates with the posterior border of the vertical part of the palatine bone.

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This article was originally based on an entry from a public domain edition of Gray's Anatomy. As such, some of the information contained herein may be outdated. Please edit the article if this is the case, and feel free to remove this notice when it is no longer relevant.

Human cranial bones
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occipital bone: Foramen magnum | Squama occipitalis (Inion | Nuchal lines | Planum occipitale | Planum nuchale | Cruciform eminence | Internal occipital protuberance | Sagittal sulcus | Internal occipital crest)
Lateral parts (Hypoglossal canal | Condyloid fossa | Condyloid canal | Jugular process | Jugular tubercle) | Basilar part (Pharyngeal tubercle)

parietal bone: Parietal eminence | Temporal line | Parietal foramen

frontal bone: Squama frontalis (Frontal suture | Frontal eminence | Superciliary arches | Glabella | Supraorbital foramen | Zygomatic process | Sagittal sulcus | Frontal crest | Foramen cecum)
Pars orbitalis (Frontal sinus | Frontonasal duct)

temporal bone: Squama temporalis (Articular tubercle | Suprameatal triangle | Mandibular fossa | Petrotympanic fissure) | Mastoid portion (Mastoid foramen
Mastoid process | Mastoid notch | Occipital groove | Sigmoid sulcus | Mastoid antrum)
Petrous portion (Hiatus of the facial canal | Internal auditory meatus | Subarcuate fossa | Carotid canal | Aqueduct of cochlea | Jugular fossa | Inferior tympanic canaliculus | Mastoid canaliculus | Styloid process | Stylomastoid foramen | Petrosquamous suture) | Tympanic part (Suprameatal spine) | Zygomatic process

sphenoid bone: Sphenoidal sinuses | Ethmoidal spine | Optic foramen | Sella turcica | Fossa hypophyseos | Dorsum sellae | Posterior clinoid processes | Carotid groove | Lingula sphenoidalis | Sphenoidal conchæ | Great wings (Spina angularis | Foramen rotundum | Foramen ovale | Foramen Vesalii | Foramen spinosum | Infratemporal crest | Sulcus tubae auditivae | Small wings | Superior orbital fissure | Anterior clinoid process | Optic foramen)
Pterygoid processes (Pterygoid fossa | Scaphoid fossa | Lateral pterygoid plate | Medial pterygoid plate | Pterygoid hamulus | Sphenoidal conchæ | Sphenoidal sinuses)

ethmoid bone: Cribriform plate | Crista galli | Perpendicular plate | Labyrinth | Ethmoid sinus | Uncinate process | Middle nasal concha | Superior meatus | Superior nasal concha | Middle meatus