The globus pallidus (pale globe) forms the medial part of the lentiform nucleus.
Striatum/neostriatum = caudate nucleus (nucleus caudatus) + putamen
Lentiform nucleus = putamen + globus pallidus
Corpus striatum (dorsal division) = caudate nucleus + putamen + globus pallidus
The medial medullary lamina divides the globus pallidus into a lateral external segment (GPe) and a medial internal segment (GPi).
The globus pallidus is bounded by the putamen laterally. It is separated from the caudate nucleus by the anterior limb of the internal capsule. The ansa lenticularis runs inferiorly.
The cell density of the globus pallidus is 1/20 that of the neostriatum. Although the external segment is larger and has a higher cell density than the internal segment, the morphology of the neurons in both segments is similar. The majority of neurons are large and multipolar, with discoid dendritic arbors.