Anterior quadrangular lobule

At a glance

English

Anterior quadrangular lobule

Latin (TA2)

Lobulus quadrangularis anterior

System

Brain and spinal cord

Region

Head

Side

Paired, left and right

About the anterior quadrangular lobule

The cerebellum is divided by deep fissures into lobes and then into lobules, which are named both in the midline vermis and in the hemispheres on either side. The anterior quadrangular lobule is the hemispheric part of the anterior lobe that lies lateral to the culmen of the vermis. In the numbered scheme of Larsell it corresponds to hemispheric lobules IV and V (H IV–H V).

On the upper surface of the cerebellum it lies behind the wing of the central lobule and in front of the primary fissure, the deep cleft that separates the anterior lobe from the posterior lobe. Behind the primary fissure lies the posterior quadrangular lobule, also called the simple lobule. Like other parts of the cortex it is folded into thin transverse folia with a core of white matter.

Functionally the anterior lobe belongs mainly to the spinocerebellum. The vermis and the nearby paravermal parts of the hemisphere receive spinocerebellar input carrying information from muscles and joints, and they hold a map of the body in which the legs are represented in the more anterior lobules and the arm further back. Through the interposed nuclei and the cerebellar outflow they help to adjust posture, muscle tone and the accuracy of limb movement on the same side of the body.

Damage to the anterior lobe and the adjacent upper vermis, such as the degeneration seen with long-term heavy alcohol use, produces a broad-based, unsteady gait with relatively little effect on the arms or speech.

Function and supply

Function

Helps coordinate posture, gait and the accuracy of limb movements on the same side, using spinocerebellar information from muscles and joints.

Blood supply

The superior cerebellar artery, which supplies the upper surface of the cerebellum.