What happens to fluid movement in the body when there are not enough plasma proteins in circulation?

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.

Choice A reason: Increased skin pigmentation is associated with Addison’s disease due to elevated ACTH stimulating melanocytes. Cushing syndrome, caused by excess cortisol, typically causes skin thinning and bruising, not hyperpigmentation. The excess cortisol does not directly affect melanin production, making this choice incorrect.

Choice B reason: Cushing syndrome leads to weight gain, not weight loss, due to cortisol’s promotion of fat deposition in central areas (e.g., abdomen, face). Increased appetite and altered metabolism contribute to obesity, not weight loss, making this choice incorrect as it contradicts the metabolic effects of hypercortisolism.

Choice C reason: Cushing syndrome often causes hypertension, not decreased blood pressure, due to cortisol’s mineralocorticoid effects, increasing sodium retention and vascular resistance. Decreased blood pressure is more associated with adrenal insufficiency, making this choice incorrect as it does not align with Cushing syndrome’s pathophysiology.

Choice D reason: Cushing syndrome, characterized by excess cortisol, suppresses the immune system by inhibiting inflammatory responses and reducing lymphocyte activity. This increases susceptibility to infections and impairs wound healing, making decreased immune response a hallmark complication, which is why this choice is correct.