Question

1. Ascending tracts into the CNS are composed of how many cells?
   a. 4 cells with all cells terminating in the thalamus
   b. 2 cells with the first cell being an interneuron
   c. 3 cells with the first cell in the ventral root
   d. 3 cells with the first cell in the dorsal root
   e. 3 cells with an interneuron in the brain

Answer 1

correct answer is option D ( 3 cells with first cell in dorsal root).

The ascending tract of CNS contains 3 types of cells-

1. First order neurons- carry sensory information form receptors to spinal cord. The sensations comes from dorsal root ganglion of spinal cord.

2. Second order neurons- carry information from spinal cord to brain.

3. Third order neurons- present in subcortical areas.

The sensory information comes form dorsal root whereas motor information travels through ventral root.