Horizontal section of the brain: Section A (Latin)

This image highlights the left side of the brain seen on a horizontal section at the level of the genu corporis callosi (A). The most striking gray matter structures seen in this section are the thalamus, located deep in the white matter, and the corpus striatum, which are the nucleus caudatus (only the caput and cauda nuclei caudati are visible), putamen and globus pallidus. In addition, we see the white matter tracts (capsula interna, externa and extrema) in both section A and B: note the different parts of the capsula interna (crus anterius, genu, crus posterius and pars retrolentiformis). Section A reveals some parts of the white matter bundles that connect the two brain hemispheres, particularly the genu and splenium corporis callosi and the columna and crus fornicis. The ventriculus tertius as well asa the cornu frontale and cornu occipitale of the ventriculus lateralis can be identified. The cornu frontale of the ventriculus lateralis on the left side is separated from its right counterpart by a thin, vertical membrane called septum pellucidum, that extends from the corpus callosum above and the fornix below.