skullbasen

Skullbasen, or the skull base, is the inferior surface of the skull that forms the floor of the cranial cavity. It provides structural support for the brain and serves as a conduit for nerves and vessels passing between the brain and the face, neck, and orbits. The base supports the brainstem and houses openings for sensory and vascular structures entering or leaving the cranial cavity.

Anatomically, it is divided into three cranial fossae: anterior, middle, and posterior. The anterior fossa includes the frontal bone, portions of the ethmoid and sphenoid bones; the middle fossa contains the sphenoid body and greater and lesser wings and parts of the temporal bones; the posterior fossa is formed primarily by the occipital bone and portions of the temporal bones. The bones of the skull base together create a complex floor that integrates the nasal cavity and the middle and inner ear regions.

The skull base contains numerous foramina and canals that transmit cranial nerves and major vessels. Examples include the cribriform plate (olfactory nerves), optic canal, superior orbital fissure, foramen rotundum, foramen ovale, foramen spinosum, carotid canal (internal carotid artery), internal acoustic meatus (facial and vestibulocochlear nerves), jugular foramen (glossopharyngeal, vagus, and accessory nerves and the internal jugular vein), hypoglossal canal (hypoglossal nerve), and the foramen magnum (medulla oblongata and vertebral arteries). The sphenoid region also contains the sella turcica, housing the pituitary gland.

Clinical relevance is notable for basilar skull fractures and skull base tumors. Imaging modalities such as CT are preferred for evaluating bony detail and fractures, while MRI provides soft-tissue and neural structure assessment. In medical terminology, skull base is the standard term in English; skullbasen appears in some Nordic languages to denote the same concept.