(also sphenoid bone) A compound bone which forms the base of the cranium, behind the eye and below the front part of the brain. It has two pairs of broad lateral ‘wings’ and a number of other projections, and contains two air-filled sinuses.
- A large groove (sinus of Breschet) may occur on the intracranial face, parallel to the coronal suture and extending from the bregma to the lesser wing of the sphenoid.
- Another such feature are the deep internasal cavities on either side of the sphenoid.
- Metastasis to the brain can occur by way of Batson's plexus or by direct extension from adjacent structures such as the sphenoid bone or sinuses.
Relating to the sphenoid bone.
- The maxillary sinus is most commonly involved; however, most patients with radiologic maxillary sinusitis have abnormalities of the ethmoid and sphenoid sinuses.
- Magnetic resonance imaging showed a mass bilaterally in the nasopharynx and the sphenoid sinuses.
- Its accuracy, however, is questionable in suspected ethmoid, frontal, or sphenoid involvement.
- Example sentences
- Branches of the nasal nerve have been described passing to the frontal, ethmoidal, and sphenoidal sinuses.
- The middle meningeal gives rise, in about 50% of cases, to an accessory meningeal artery, which also enters the skull via the foramen ovale, or the emissary sphenoidal foramen.
- The ophthalmic artery may be associated with the development of a branch of the lacrimal artery that passes through the sphenoidal fissure to anastomose with the middle meningeal artery.
Mid 18th century: from modern Latin sphenoides, from Greek sphēnoeidēs, from sphēn 'wedge'.
For editors and proofreaders
Line breaks: sphen|oid
Definition of sphenoid in:
What do you find interesting about this word or phrase?
Comments that don't adhere to our Community Guidelines may be moderated or removed.