Final answer:
Parkinson's and Alzheimer's diseases are neurodegenerative disorders affecting the brain and body. Parkinson's involves the loss of dopamine neurons causing motor dysfunction, while Alzheimer's features plaque accumulation leading to memory and cognitive decline. Both diseases are complex and not fully understood.
Step-by-step explanation:
Parkinson's disease and Alzheimer's disease are both neurodegenerative disorders that adversely affect the brain and body. Parkinson's disease is characterized by the loss of dopamine-producing neurons in the substantia nigra, which is a region of the midbrain. This neuron loss leads to various motor symptoms such as tremors, slowed movement, rigid muscles, and postural instability. Cognitive impairments, including dementia and depression, are also common as the disease progresses.
Alzheimer's disease, on the other hand, is principally associated with the accumulation of beta-amyloid plaques and neurofibrillary tangles in the brain, leading to neuron degeneration and brain atrophy, particularly in the hippocampus and ventricles. This degeneration causes memory loss, confusion, and a decline in cognitive functions. The exact causes of both diseases are not fully understood, but they may involve a combination of genetic and environmental factors. In Parkinson's disease, the presence of Lewy bodies in neurons correlates with the severity of the disease.