This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
[{'content': 'The maximum rate of axonal transport is: \nSelect and explain. \nA. 200 mm/day, B. 400 mm/day, C. 600 mm/day, D. 800 mm/day', 'role': 'user'}, {'content': 'Answer: B \nExplanation: AXONAL TRANSPORT\u200b\nThe apparatus for protein synthesis in neurons is located primarily in the soma, with transport of proteins and polypeptides to the axonal ending by axoplasmic flow. Thus, the cell body maintains the functional and anatomic integrity of the axon. Orthograde transport occurs along microtubules located along the length\u200b of the axon; it requires two molecular motors, dynein and kinesin. Orthograde transport moves from the cell body toward the axon terminals. It has both fast and\xa0slow components, fast axonal transport occurs at about 400 mm/day, and slow axonal transport occurs at 0.5–10 mm/day. Retrograde transport from the nerve ending to the cell body occurs at about 200 mm/day.\n\xa0\nReference: Ganong’s Review of Medical Physiology 26th ed pdf no 231', 'role': 'assistant'}]