Sagittal Section of the Dura Mater

Description

Running in sagittal section from the cranial cavity into the vertebral canal, the dura mater (pachymeninx) lines the inner table of the calvaria and continues caudally as the spinal dura surrounding the spinal cord. Medial reflections of the cranial dura form the falx cerebri between the cerebral hemispheres and the tentorium cerebelli over the cerebellum, with the brainstem positioned inferior to the diencephalon and anterior to the cerebellum. Along the superior aspect of the cranial vault, separation of periosteal and meningeal dural layers creates the dural venous sinuses, with the superior sagittal sinus expected at the attached margin of the falx and the straight sinus at its junction with the tentorium. Nerve roots exit laterally from the spinal cord within the vertebral canal. Dural reflections and venous sinuses matter because they define the fixed compartments that shift during mass effect and they provide the low-pressure venous drainage routes vulnerable to tearing. Subdural hematoma classically arises from rupture of bridging veins coursing from cerebral cortex to a dural sinus, while epidural hematoma collects between calvaria and periosteal dura, often near the middle meningeal artery. In the spine, the sagittal relationship of cord, dura, and posterior elements supports teaching of epidural anesthesia placement and why a midline approach targets the epidural space before the dura is breached. Neuroanatomy and head-and-neck courses use this sagittal membrane section to teach meningeal layers, dural partitions, and venous sinus anatomy in one plane, and neurosurgical texts use it to orient approaches to the falx, tentorium, and posterior fossa. Radiology educators can pair it with midline MRI to explain where extra-axial collections sit relative to dura and brain. Anatomical accuracy verified by SciePro's Medical Advisory Board.