Meningiomas are named according to their location (Fig 1) and cause various symptoms: 1  Convexity meningiomas: grow on the surface of the brain. They may not produce symptoms until they reach a large size. 2  Falx and parasagittal meningiomas: grow from the dura fold that runs between the left and right sides of the brain.
Tectum | Tegmentum | See also. The midbrain, or mesencephalon is made up of two main structures and surrounds the cerebral aqueduct.he midbrain, or mesencephalon is made up of two main structures and surrounds the cerebral aqueduct.
In the brain, the dura mater is made up of two layers of whitish, nonelastic film or membrane. The outer layer is called the periosteum. An inner layer, the dura, lines the inside of the entire skull and creates little folds or compartments in which parts of the brain are protected and secured.