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.
The hair shaft is made of a hard protein called keratin and is made in three layers. This protein is actually dead, so the hair that you see is not a living structure. The inner layer is the medulla. The second layer is the cortex and the outer layer is the cuticle. The cortex makes up the majority of the hair shaft.