Arachnoid Mater, Ventral View

Description

Viewed from the ventral aspect, the arachnoid mater forms a thin, translucent meningeal membrane draped over the inferior surface of the cerebral hemispheres, bridging across the deep fissures while sending trabeculae toward the pia mater within the subarachnoid space. At the base, it spans the longitudinal fissure and the interpeduncular and sylvian cistern regions, covering sulci rather than dipping into each one, so the gyri of the orbital frontal cortex, temporal poles, and the ventral surface of the cerebellar hemispheres read as contour beneath a continuous sheet. Yellow elements in the basal field logically correspond to cranial nerves as they traverse the subarachnoid space toward their foramina, with the arachnoid forming sleeves around their root entry and exit zones. Fine perforations and punctate markings can be interpreted as vessel and nerve passage points through cisternal spaces. Delicate anatomy. This ventral orientation matters because most clinically relevant subarachnoid cisterns sit at the cranial base, where blood from a ruptured berry aneurysm in the circle of Willis typically accumulates and tracks along arachnoid-lined spaces. Blood products and inflammation at the basal cisterns can impair CSF resorption at arachnoid granulations and contribute to communicating hydrocephalus, and the same cisternal pathways explain why meningitis often presents with cranial neuropathies. For skull base and suprasellar surgery, the arachnoid planes around the optic chiasm, internal carotid artery, and oculomotor nerve define safe dissection corridors and predictable points of adhesion. Use this artwork for neuroanatomy and head and neck courses when teaching meningeal layers, subarachnoid cisterns, and cranial nerve relationships at the ventral brain, and for neurosurgical atlases covering cisternal approaches, aneurysmal SAH distribution patterns, or basal meningitis. It also suits patient-facing materials explaining why hemorrhage at the brain base causes sudden headache and cranial nerve deficits. Anatomical accuracy verified by SciePro's Medical Advisory Board.