Dorsalis nucleus

Nucleus dorsalis/thoracicus

Dorsal nucleus of the spinal cord, Columna clarkii

The core is stretched, on hay. and we. side of the spinal cord, from segment T1 down to segment L2 or L3. The nucleus is located in the intermediate gray matter at the base of the hind horn and receives a strong influx of nerve fibers from the fasciculus gracilis.

The incoming nerve fibers convey signals from the joints and muscles of the lower extremity as well as from the skin in the sole of the foot. These signals contain information about how the muscles of the lower extremity act( i.e. information about the length, length change and force development of each individual muscle, as well as the angular velocity of the different joints of the extremity, in other words . proprioceptive information). In addition, information about how the body weight is distributed via the soles of the feet over the surface.

The nucleus processes the information and transmits the result via the posterior spino-cerebellar pathway (tractus spino-cerebellaris posterior) to the cerebellum.

Note that the dorsalis nucleus thus receives much the same proprioceptive information that the nucleus gracilis up in the medulla receives. Then notice that the nucleus dorsalis transmits the information to the cerebellum on the same side via the tractus spino-cerebellaris posterior, but that the nucleus gracilis, via the medial limb and VPL nucleus of the thalamus, transmits the information to the primary sensory cortex on the opposite side and one becomes aware of the movements one is performing.