Which manifestation is associated with hypothyroidism?

Choice A reason: Platelet-activating factor promotes platelet aggregation and inflammation but does not directly cause redness. Redness in acute inflammation results from increased blood flow to the affected area, driven by vascular changes, not primarily platelet activity, making this choice incorrect.

Choice B reason: Vasodilation, triggered by inflammatory mediators like histamine, increases blood flow to the inflamed area, causing redness (erythema). Dilated vessels allow more oxygenated blood to reach tissues, a hallmark of acute inflammation, making this the correct pathophysiological process for redness.

Choice C reason: Increased capillary permeability allows fluid and proteins to leak into tissues, causing swelling (edema) in inflammation. While it contributes to inflammation, it does not directly cause redness, which is due to increased blood flow, making this choice incorrect.

Choice D reason: Vasoconstriction reduces blood flow, causing pallor, not redness. In acute inflammation, vasodilation predominates to deliver immune cells and nutrients, while vasoconstriction is an initial transient response, making this choice incorrect for causing redness.

Choice A reason: Abnormal tau proteins contribute to Alzheimer’s, forming neurofibrillary tangles, but damage is not limited to the frontal lobe. The hippocampus and other regions are primarily affected, leading to memory loss. This choice is too specific and incomplete, making it incorrect.

Choice B reason: Damaged blood vessels interrupting brain blood flow describe vascular dementia, not Alzheimer’s. Alzheimer’s involves neuronal degeneration from protein accumulation, not primarily vascular pathology, although vascular factors may contribute, making this choice incorrect for Alzheimer’s pathophysiology.

Choice C reason: Repeated traumatic brain injuries cause chronic traumatic encephalopathy, not Alzheimer’s. While trauma may increase Alzheimer’s risk, the primary pathology involves amyloid and tau proteins, not trauma-induced encephalopathy, making this choice incorrect for the disease’s core pathophysiology.

Choice D reason: Alzheimer’s disease is characterized by amyloid-beta plaques and tau protein tangles, which disrupt neuronal function, particularly in the hippocampus, leading to memory impairment. These protein aggregates cause synaptic loss and neurodegeneration, accurately describing the disease’s pathophysiology, making this the correct choice.