Final answer:
Alzheimer's disease is a neurodegenerative disease characterized by the progressive death and degeneration of neurons in the brain. It is named after Alois Alzheimer, who first described the presence of amyloid plaques and neurofibrillary tangles in affected brains. The causes of the disease are still not fully understood.
Step-by-step explanation:
What is Alzheimer's disease?
Alzheimer's disease is a neurodegenerative disease characterized by the progressive death and degeneration of neurons in the brain. It leads to increasing memory loss and eventual dementia. The disease is named after Alois Alzheimer, a German psychiatrist who first described the presence of abnormal clumps called amyloid plaques and tangled brain fibers called neurofibrillary tangles in the brains of affected individuals. These hallmarks of the disease, along with an overall shrinking of brain volume, are commonly observed in Alzheimer's patients.
What are amyloid plaques and neurofibrillary tangles?
Amyloid plaques are dense conglomerations of beta-amyloid protein fragments that accumulate between brain cells. Neurofibrillary tangles are twisted fibers made up of a protein called tau that build up inside neurons. Both amyloid plaques and neurofibrillary tangles are associated with the loss of synapses between neurons and the death of neurons in Alzheimer's disease.
What are the causes of Alzheimer's disease?
The exact cause of Alzheimer's disease is still unknown. However, one prevailing theory suggests that the accumulation of beta-amyloid plaques plays a significant role in the development of the disease. Another theory involves the misshapen tau protein, which forms neurofibrillary tangles and disrupts neuronal functioning. Research is ongoing to determine the precise causes of Alzheimer's disease.