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 midbrain is divided into two parts: the sensory component, the tectum (meaning roof) and the motor structure, the tegmentum (meaning floor). The tectum receives a massive amount of sensory information from the eyes and ears.he midbrain is divided into two parts: the sensory component, the tectum (meaning roof) and the motor structure, the tegmentum (meaning floor). The tectum receives a massive amount of sensory information from the eyes and ears.