The Mesencephalon is a part of the brain that is also known as the “Mid Brain”. Its structure is made up of the brainstem which connects all the spaces of the brain (the brainstem bridge, the cerebellum and the diencephalon). Its position can be deduced from its other name, “Mid Brain”, because the Mesencephalon is located in the inner central part of the entire brain mass. Through this section of the brain, there is a conduit through which the cerebrospinal fluid passes, which is responsible for the mechanical stability of the body among other things.

Specifically, the function of the Mesencephalon is the conduction and control of motor impulses that go from the cerebral cortex to the junction of the spinal cord and the brain (brain bridge). It is also responsible for the sensory impulses that manifest in the spinal cord. A section of the Mesencephalon called Superior Quadrigeminal Tubercles is responsible for the movements made by the eyeballs as a sensory response to any stimulus that provokes the sense of sight, this is because the oculomotor nerve is located here. The inner quadrigeminal tubercles record auditory stimuli perceived by the ear as well as related head movements.

In Mesencephalon for its study it can be divided into three parts or faces: an anterior part of triangular shape in which the optic chiasm and the optic tracts are contained, which are part of the eyes, in the lateral part is the conjunctival arm connected with medial and medial geniculate body. On the back are the already explained quadrigeminal tubercles, there are 4 of them, clearly divided into upper and lower ones.