In: Anatomy and Physiology
Which nerve fiber tract sends orders from the Primary Motor Area to the somatic motorneurons?
A. Spinocerebellar
B. Dorsal (White) Columns
C. Extrapyramidal
D. Pyramidal
E. Spinothalamic
D. Pyramidal
Explanation
The primary motor area or the motor cotrex located at the precentral gyrus and from there upper motor neurons gets originated . The axon from the motor cortex emerges and forms the nerve tract the corticospinal tract. Thus cortico motor neurons get originated from the primary motor cortex over the motor neurons in the ventral horn area of the spinal cord.Then it moves to the axon synapse to spinal motor neurons to the somatic regions.The lateral and anterior corticospinal tracts includes the pyramidal tracts.
Spinocerebellar nerve tract emerges from the spinal cord and terminate at the cerebellum of same side.Dorsal column tract represents the medial lemniscus pathway and convery the sensory information in CNS from the skin and joints. The Extrapyramidal tract emerges from the brain stem and convey the information to the spinal cord via motor fibers. The spinothalamic tract is the ascending route of spinal cord and convey the sensory information to the somatosensory region of thalamus.