Final answer:
In Alzheimer's disease, physical changes such as amyloid plaques, neurofibrillary tangles, and a reduction in brain volume have been identified, but an enlarged hippocampus is not one of the physical changes.
Step-by-step explanation:
In Alzheimer's disease, several physical changes have been identified in patients. These include the presence of amyloid plaques (abnormal clumps of proteins) and neurofibrillary tangles (tangled brain fibers). There is also an overall reduction in brain volume. However, an enlarged hippocampus is not one of the physical changes identified in these patients.