The globus pallidus is deep inside each cerebral hemisphere, one on each side: a wedge of grey matter tucked just inside the putamen and just outside the internal capsule, near the centre of the brain. [1][2]
The 3D brain needs JavaScript. The text below still says where the globus pallidus is and what it does.
Slice
Opens cut by a front (coronal) slice through the globus pallidus. Drag to turn, pinch or scroll to zoom, tap any part to name it; .
Takes part in: movement — see every part of each lit together.
Where it is
A major part of the basal ganglia with two adjacent segments, the external (GPe) and internal (GPi), divided by a thin sheet called the medial medullary lamina. It is part of the telencephalon but keeps close functional ties with the subthalamus in the diencephalon. [1]
With the putamen, which wraps around its outer side, it forms the lentiform nucleus; the internal capsule runs along its inner side. [3][4]
It is one of the main parts of the basal ganglia, with the striatum (caudate nucleus and putamen), the substantia nigra and the subthalamic nucleus. [2]
What it does
It is involved in regulating voluntary movement, as part of the basal ganglia, which regulate movements that happen at a subconscious level: the constant, subtle adjustment that lets you walk without thinking about each step. [1]
Its output is inhibitory (GABA): the internal segment is one of the main output stations of the basal ganglia, holding the thalamus in check until a movement is selected. [2]
OpenStax describes the basal nuclei as comparing what the cortex is doing with the general state of activity in the nervous system, to influence how likely a movement is to happen: they keep a student sitting in a lecture from acting on an urge to jump up and shout. [5]
Connections
Main input from the striatum (caudate nucleus and putamen); it receives no direct input from the cortex. [1]
Main direct outputs to the thalamus and the substantia nigra. In the indirect pathway the external segment sends a GABA projection to the subthalamic nucleus. [1][6]
Inside it
It is crossed by the many myelinated nerve fibres of the striatopallidonigral bundle, which give it the pale look it is named for. [1]
Other names
Latin for “pale globe”. Also called the paleostriatum or the dorsal pallidum. [1]
Size
On this model the left globus pallidus measures about 29 mm front to back, 17 mm top to bottom and 17 mm side to side (the box it fits in, not its volume); the right one is its mirror image. [7]
Centre of the left globus pallidus compared with the centre of the left putamen: 4 mm closer to the midline; 5 mm apart in a straight line. [7]
Centre of the left globus pallidus compared with the centre of the left thalamus: 18 mm further forward, 11 mm further from the midline; 21 mm apart in a straight line. [7]
Facts describe anatomy and normal function only. The 3D model is the adult male BodyParts3D brain (credits and licence); real brains vary in size and shape, so its measurements describe one model, not anyone’s brain.