OSMT (Ontario Society of Medical Technologists) Practice Exam

The correct choice is gray matter because it is within the spinal cord where the cell bodies of motor neurons are located. Gray matter primarily consists of neuronal cell bodies, dendrites, and unmyelinated axons, which are crucial for processing and transmitting information. Specifically, in the spinal cord, the anterior or ventral horns of the gray matter are responsible for housing the cell bodies of motor neurons that innervate skeletal muscles and are essential for voluntary movement.

The other options do not contain the cell bodies of motor neurons. The dorsal root ganglion, for instance, contains the cell bodies of sensory neurons, while the white matter consists primarily of myelinated axons that form pathways for communication between different segments of the nervous system. The ventral root consists of the axons that exit the spinal cord to form peripheral nerves, but it does not contain the cell bodies of motor neurons. Therefore, identifying gray matter as the location of motor neuron cell bodies is crucial for understanding the organization of the spinal cord and overall neuromuscular function.