Anterior corticospinal tract

Anterior Corticospinal Tract

Diagram showing the course of the corticospinal tracts. The anterior corticospinal tract is labeled at the bottom center.

The Anterior Corticospinal Tract (ACT) is a component of the Central Nervous System (CNS) that plays a crucial role in the transmission of motor impulses from the brain to the spinal cord. It is one of the two main corticospinal tracts, the other being the lateral corticospinal tract.

Anatomy

The anterior corticospinal tract originates in the motor cortex of the brain. It descends through the internal capsule, cerebral peduncle, and pons before decussating (crossing over) in the medulla oblongata. Unlike the lateral corticospinal tract, which decussates completely, only 10-15% of fibers in the anterior corticospinal tract decussate.

Function

The anterior corticospinal tract is involved in the control of bilateral postural and skilled voluntary movements, particularly of the axial and girdle muscles. It carries motor impulses from the brain to the spinal cord, which are then relayed to the muscles.

Clinical Significance

Damage to the anterior corticospinal tract can result in a variety of motor deficits, including spastic paralysis, muscle weakness, and Babinski sign. These symptoms are typically seen in conditions such as stroke, multiple sclerosis, and spinal cord injury.

See Also

• Motor neuron
• Upper motor neuron
• Lower motor neuron
• Pyramidal tracts