Question

Which pathway of upper motor neurons is correct?

A. Lower motor neurons in the lateral ventral horn go to axial and proximal limb muscles helping with posture and balance
B. Upper motor neurons in the cerebral cortex travel through lateral white matter of the spinal cord on their way to lower motor neurons in the lateral ventral horn
C. Lower motor neurons in the medial ventral horn go to distal limb muscles aiding in skilled movement
D. Upper motor neurons in the brainstem travel through lateral white matter of the spinal cord on their way to lower motor neurons in the medial ventral horn
E. Upper motor neurons in the cerebral cortex travel bilaterally to lower motor neurons in the medial ventral horn and lateral ventral horn

Answer 1

The correct pathway of upper motor neurons is that they originate in the cerebral cortex and travel through the lateral white matter of the spinal cord to synapse with lower motor neurons in the lateral ventral horn.

Step-by-step explanation:

The correct pathway of upper motor neurons is described in option B. It states, "Upper motor neurons in the cerebral cortex travel through lateral white matter of the spinal cord on their way to lower motor neurons in the lateral ventral horn." Upper motor neurons have their cell bodies in the primary motor cortex and project their axons to synapse with lower motor neurons, which are located in the ventral horn of the spinal cord.

The corticospinal tract is the major descending pathway that controls skeletal muscle movements. The descending axons from the cortex mostly cross over to the opposite side (contralateral) in the medulla before reaching the spinal cord. Conversely, the anterior corticospinal tract, which doesn't cross at the medulla, controls the muscles of the body trunk and the lower motor neurons here are located in the medial regions of the ventral horn.