on inner aspect of middle cranial fossa 3 foramina are oriented along an oblique line in the greater sphenoidal wing from anteromedial behind the superior orbital fissure to posterolateral
mnemonic: “rotos”
- foramen rotundum
- foramen ovale
- foramen spinosum
= canal within greater sphenoid wing connecting middle cranial fossa + pterygopalatine fossa
Location: inferior and lateral to superior orbital fissure
Course: extends obliquely forward + slightly inferiorly in a sagittal direction parallel to superior orbital fissure
Contents: (a) nerves: V2 (maxillary nerve)
(b) vessels: (1) artery of foramen rotundum
(2) emissary vv.
- best visualized by coronal CT
= canal connecting middle cranial fossa + infratemporal fossa
Location: medial aspect of sphenoid body, situated posterolateral to foramen rotundum (endocranial aspect) + at base of lateral pterygoid plate (exocranial aspect)
Contents: (a) nerves: (1) V3 (mandibular nerve)
(2) lesser petrosal nerve (occasionally)
(b) vessels: (1) accessory meningeal artery
(2) emissary veins
Location: on greater sphenoid wing posterolateral to foramen ovale (endocranial aspect) + lateral to eustachian tube (exocranial aspect)
Contents: (a) nerves: (1) recurrent meningeal branch of mandibular nerve
(2) lesser superficial petrosal nerve
(b) vessels: (1) middle meningeal artery
(2) middle meningeal vein
covered (occasionally) by fibrocartilage, carotid artery rests on endocranial aspect of fibrocartilage
Location: at base of medial pterygoid plate
Contents: (inconstant)
(a) nerve: pterygoid canal n. (actually pierces cartilage)
(b) vessel: meningeal branch of ascending pharyngeal a.
basion = anterior lip of foramen
opisthion = posterior lip of foramen
Contents: (a) nerves: (1) medulla oblongata
(2) CN XI (spinal accessory nerve)
(b) vessels: (1) vertebral artery
(2) anterior spinal artery
(3) posterior spinal artery
= VIDIAN CANAL
= within sphenoid body connecting pterygopalatine fossa anteriorly to foramen lacerum posteriorly
Location: at base of pterygoid plate below foramen rotundum
Contents: (a) nerves: vidian nerve = nerve of pterygoid canal = continuation of greater superficial petrosal nerve (from cranial nerve VII) after its union with deep petrosal nerve
(b) vessel: vidian artery = artery of pterygoid canal = branch of terminal portion of internal maxillary a. arising in pterygopalatine fossa → passing through foramen lacerum posterior to vidian n.
= ANTERIOR CONDYLAR CANAL
Location: in posterior cranial fossa anteriorly above condyle starting above anterolateral part of foramen magnum, continuing in an anterolateral direction + exiting medial to jugular foramen
Contents: (a) nerves: cranial nerve XII (hypoglossal n.
(b) vessels: (1) pharyngeal artery
(2) branches of meningeal artery
Location: at posterior end of petrooccipital suture directly posterior to carotid orifice
- anterior part:
- inferior petrosal sinus
- meningeal branches of pharyngeal artery + occipital a.
- intermediate part:
- cranial nerve IX (glossopharyngeal nerve)
- cranial nerve X (vagus nerve)
- cranial nerve XI (spinal accessory nerve)
- posterior part: internal jugular vein