Quadrigeminal Artery inside the Skull

Description

Removed calvaria exposes the male cranial cavity and internal cranial base, with the arterial tree draped along the endocranial surface and clustered around the midline. Centered at the level of the midbrain tectum (quadrigeminal plate), the quadrigeminal artery is shown as a small-caliber vessel arising from the posterior circulation and coursing posteriorly toward the region of the superior and inferior colliculi, in close relationship to the tentorial incisura. An arterial ring consistent with the Circle of Willis sits inferior and anterior to this territory, linking the internal carotid system to the basilar apex and posterior cerebral arteries, from which arterioles and small vascular branches radiate laterally across the skull base. Attention to the quadrigeminal region matters because this is where posterior circulation anatomy becomes clinically unforgiving: small arteries at the basilar tip and proximal posterior cerebral artery supply the midbrain, thalamus, and tectum, and they are implicated in infarcts that present with vertical gaze palsy or altered pupillary responses. Neurosurgical approaches that work around the tentorium, including pineal and posterior fossa corridors, demand a clear mental map of vessels near the tectum to avoid perforator injury. Tiny vessel, major consequence. Use this illustration in neuroanatomy and neuroradiology teaching when introducing the Circle of Willis, basilar apex branching patterns, and cross section orientation of posterior circulation vessels within the skull. It also suits textbook figures and conference slides on basilar tip aneurysm planning, pineal region surgery, and midbrain stroke syndromes where spatial relationships to the cranial base and tentorial edge need to be explicit. Anatomical accuracy verified by SciePro's Medical Advisory Board.