Tractus reticulospinalis lateralis

The medial reticular formation and lateral reticular formation are two columns of nuclei with ill-defined boundaries that send projections through the medulla and into the midbrain.

The nuclei can be differentiated by function, cell type, and projections of efferent or afferent nerves.

Moving caudally from the rostral midbrain, at the site of the rostral pons and the midbrain, the medial RF becomes less prominent, and the lateral RF becomes more prominent.

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The reticulospinal tracts, also known as the descending or anterior reticulospinal tracts, are extrapyramidal motor tracts that descend from the reticular formation in two tracts to act on the motor neurons supplying the trunk and proximal limb flexors and extensors.

The reticulospinal tracts are involved mainly in locomotion and postural control, although they do have other functions as well.

The descending reticulospinal tracts are one of four major cortical pathways to the spinal cord for musculoskeletal activity.

The reticulospinal tracts works with the other three pathways to give a coordinated control of movement, including delicate manipulations.

The four pathways can be grouped into two main system pathways – a medial system and a lateral system.

The medial system includes the reticulospinal pathway and the vestibulospinal pathway, and this system provides control of posture.

The corticospinal and the rubrospinal tract pathways belong to the lateral system which provides fine control of movement.