FORAMINA
IN THE BASE OF THE ADULT SKULL
The foramina in the
base of the skull allow major nerves and blood vessels to course through the
skull. Pressure, traction, and masses can damage structures traversing these
small spaces that snugly confine the structures.
CLINICAL POINT
The foramina of the skull
are narrow openings that allow the passage of nerves and blood vessels. Under
normal circumstances, there is enough room for comfortable passage of these
structures without traction or pressure. However, with the presence of a tumor
at a foramen, the passing structures can be compressed or damaged. For example,
a tumor at the internal acoustic meatus can result in ipsilateral facial and
vestibuloacoustic nerve damage, and a tumor at the jugular foramen can result
in damage to the glossopharyngeal, vagus, and spinal accessory nerves.
Foramen cecum Vein to superior sagittal sinus, Anterior ethmoidal foramen Anterior ethmoidal artery, vein and nerve
Foramina of cribriform plate Olfactory nerve bundles, Posterior ethmoidal foramen Posterior ethmoidal artery, vein and nerve, Optic (II) nerve Ophthalmic artery, Oculomotor (III) nerve Trochlear (IV) nerve, Superior orbital fissure Ophthalmic nerve, Abducens (VI) nerve Superior ophthalmic vein, Foramen rotundum Maxillary nerve, Mandibular nerve Accessory meningeal artery Lesser petrosal nerve
(occasionally), Middle meningeal artery and vein Foramen
spinosum Meningeal branch of mandibular nerve, Foramen of Vesalius Small emissary vein (inconstant), Foramen lacerum Internal carotid artery, Internal carotid nerve plexus, Hiatus of canal of Lesser petrosal nerve Hiatus of canal of Greater
petrosal nerve, Facial (VII) nerve, Internal acoustic meatus Vestibulocochlear (VIII) nerve, Labyrinthine artery Vestibular aqueduct Endolymphatic duct, Mastoid foramen Emissary vein (inconstant) Branch of occipital artery, Inferior petrosal sinus Glossopharyngeal (IX) nerve, Jugular foramen, Vagus (X) nerve Accessory (XI) nerve
Sigmoid sinus, Posterior meningeal artery Emissary vein, Condylar canal Meningeal branch of (inconstant) ascending pharyngeal
artery, Hypoglossal canal Hypoglossal (XII) nerve, Medulla oblongata Foramen magnum Meninges, Vertebral arteries, Spinal roots of accessory nerves
