Question

Neurofibrillary tangles are

a. clumps of dead neurons in the brains of Alzheimer's patients.
b. senile plaques in the brains of Alzheimer's patients.
c. abnormal tangles of neurofilaments.
d. patches of dead and dying axons.

Answer 1

Neurofibrillary tangles in Alzheimer's disease are abnormal tangles of neurofilaments formed by hyperphosphorylated tau protein inside neurons, disrupting the cells' function and contributing to the disease's cognitive symptoms.

Step-by-step explanation:

Neurofibrillary tangles are a characteristic feature of Alzheimer's disease and can be defined as abnormal tangles of neurofilaments within neurons. These tangles are composed of tau protein that has become hyperphosphorylated, leading to its accumulation inside nerve cells, which impedes their normal function. The presence of neurofibrillary tangles, along with amyloid plaques and a general decrease in brain volume, are hallmarks of Alzheimer's pathology, with significant neuron loss noted in the hippocampus, a region critical for memory.