QS Study

Tracts are a bundle of nerve fibers within CNS have the same origin, same destination, and the same function.

Descending tracts or Motor tracts: The descending tracts are the pathways by which motor signals are sent from the brain to lower motor neurons. The effecting of movements that are more difficult than spinal reflexes depends upon the activation of networks of neurons in the motor cortex and brainstem. Because the brainstem nuclei and cortical motor areas correspond straight with the local controls of the spinal cord they are known as the descending pathways.

(1) Pyramidal Tracts: These tracts originate in the cerebral cortex, carrying motor fibers to the spinal cord and brain stem. They are responsible for the voluntary control of the musculature of the body and face.

  • Lateral corticospinal tract (crossed pyramidal tract)
  • Anterior corticospinal tract ( Direct pyramidal tract)

(2) Corticobulbar tracts – supplies the musculature of the head and neck.

(3) Extrapyramidal tracts: They are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture, and locomotion.

  • Rubrospinal,
  • Tectospinal tract and tectobulabar tract,
  • Reticulospinal tract,
  • Vestibulospinal tract,
  • Olivospinal tract (Bulbospinal tract).