Point 4











Point 4. Nucleus Gracilis and Cuneatus and the ML

As you have learned in the spinal cord module, axons in the fasciculus gracilis and fasciculus cuneatus are the uncrossed central processes of alpha­beta fibers whose cell bodies lie in the dorsal root ganglia. Fibers in fasciculus gracilis end in nucleus gracilis, while fibers in fasciculus cuneatus end in nucleus cuneatus.

Nucleus gracilis and nucleus cuneatus lie in the dorsal portion of the caudal medulla. These two nuclear groups and their associated fasciculi can be seen as slight swellings on the dorsal surface of the medulla. The bump formed by nucleus and fasciculus gracilis is called the gracile tubercle (or clava; L., club) and that caused by nucleus and fasciculus cuneatus is called the cuneate tubercle. These bumps can be seen on both of the drawings shown below.


Level 2. Decussation of the Medial Lemniscus

Brainstem - Dorsal View

Level 2. Decussation of the Medial Lemniscus