The final brain, cerebrum, represents the most massive department of a brain (the biggest on the volume and quantity of nervous cages) and fills the most part of a cavity of a brain skull. It consists of two hemispheres and the calloused body connecting them.
The surface of a raincoat has very difficult drawing consisting from alternating among themselves in various directions of the furrows and rollers between them called by crinkles, gyri. The size and a form of furrows are subject to considerable individual fluctuations owing to what not only a brain of various people, but even hemispheres of the same individual on drawing of furrows are not quite similar.
In the top departments of a forward surface of a medulla from each party of a median crack, fissura mediana, the roller, a pyramid (oblong a brain, pyramis (medullae oblongatae) settles down a cone-shaped form.
On cross-sections of a medulla it is possible to distinguish that each pyramid represents a complex of bunches which (it is visible if to stretch in sides of the region of a forward median crack) partially mutually cross, forming a recross of pyramids, decussatio pyramidum. Further fibers pass into system of a lateral kanatik of a spinal cord, funiculus medullae spinalis lateralis where follow as a branch cortical and spinal pyramidal track, tractus corticospinalis (pyramidalis) of lateralis. Other, smaller part of bunches, without entering a recross, follows in system of a forward kanatik of a spinal cord, funiculus anterior, as a forward cortical and spinal (pyramidal) way, tractus corticospinalis (pyramidalis) of anterior. These ways unite in a uniform pyramidal way.