Vagus, hypoglossal, and median nerves in human development.

In spite of the wealth of literature on the changes of the neurons in development of the brainstem and the spinal cord in vertebrates, the alterations of the cranial nerves and somatic nerves during the prenatal period was largely neglected. Particularly in humans, little information was available. The article reports the changes in the vagus, hypoglossal, and median nerves in the fetus and term babies. The changes of proportion of different-sized nerve fibers are documented. The patterns were different in the three nerves and the hypoglossal nerve seemed to show "pruning" of fibers during this period.