Dorsal column relay in which nucleus:
Ans. D. Gracile nucleusa. The dorsal column-medial lemniscus pathway is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception (position) from the skin and joints.b. The pathway receives information from sensory receptors throughout the body, and carries this in nerve tracts in the white matter of the dorsal columns of the spinal cord, to the medulla where it is continued in the medial lemniscus, on to the thalamus and relayed from there through the internal capsule and transmitted to the somatosensory cortex.c. There are three groupings of neurons that are involved in the pathway: first-order neurons, second-order neurons, and third-order neurons. The first-order neurons are sensory neurons located in the dorsal root ganglia, that send their afferent fibers through the two dorsal columns - the gracile fasciculus, or gracile tract, and the cuneate fasciculus or cuneate tract. The first-order axons make contact with second-order neurons at the gracile nucleus and the cuneate nucleus in the lower medulla. The second-order neurons send their axons to the thalamus. The third- order neurons are in the ventral nuclear group in the thalamus and fibres from these ascend to the postcentral gyrus.
Substantia gelatinosa
Nucleus proprius
Accessory cuneate nucleus
Gracile nucleus
Neuroanatomy