This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Nervous system, Subject name: Physiology
Pain is carried to 
Select and explain. 
A. Ventralhom, B. Dorsal horn, C. Substantia nigra, D. None of the above
B: Dorsal horn
Answer: B: Dorsal horn 
Explanation: Neurons in the spinal dorsal horn process sensory information, which is then transmitted to several brain regions, including those responsible for pain perception. The dorsal horn provides numerous potential targets for the development of novel analgesics and is thought to undergo changes that contribute to the exaggerated pain felt after nerve injury and inflammation. Dorsal horn neurons receive sensory information from primary afferents that innervate the skin and deeper tissues of the body and that respond to specific types of noxious and non-noxious stimuli. These afferents terminate in the dorsal horn with a distribution pattern that is determined by their sensory modality and the region of the body that they innervate. The incoming information is processed by complex circuits involving excitatory and inhibitory interneurons and transmitted to projection neurons for relay to several brain areas. In addition, nociceptive information is conveyed to the ventral horn and contributes to spinally-mediated nocifensive reflexes. Ref: guyton and hall textbook of medical physiology 12 edition page number:691,692,693