Occipital Bone in a Section of the Skull

Description

Centered in the posterior cranial base, the occipital bone is presented in sagittal section, with the foramen magnum opening inferiorly and framed by the basilar part anteriorly and the squamous part posteriorly. Superior to the basion, the clivus slopes anterosuperiorly toward the dorsum sellae region, while posteriorly the internal occipital surface curves to form the posterior cranial fossa. Along the midline, the internal occipital crest and adjacent grooves for the dural venous sinuses are suggested by the contoured endocranial relief. Sutural interfaces with the parietal bone at the lambdoid suture and with the temporal bone at the occipitomastoid region are readable as interdigitating osseous margins. Sagittal section is the teaching workhorse for orienting the craniovertebral junction. The relationship of the foramen magnum to the clivus and posterior fossa underpins assessment of basilar invagination and Chiari I malformation, where tonsillar descent and crowding at the foramen magnum alter CSF flow. It also maps directly to surgical corridors such as the far-lateral and transcondylar approaches for lesions ventral to the brainstem, where the occipital condyle (partly intersected by this plane) sets the limit of safe bony resection. Midline anatomy matters. Use this asset in neuroanatomy and head and neck anatomy courses when you need a clean, realistic sagittal reference for the osseous cranial base, or in textbooks and review articles discussing the clivus, posterior cranial fossa, and craniovertebral junction pathology. It also suits patient-facing materials explaining skull base decompression or posterior fossa surgery with clear bony landmarks and sutural context. Anatomical accuracy verified by SciePro's Medical Advisory Board.