MSN 570 Advanced Pathophysiology Final 2024

Correct Answer: C

Rationale: Osteosarcoma is an aggressive bone tumor that most commonly arises in the bone marrow of long bones, such as the femur or tibia. Choice A is incorrect as osteosarcoma is not a slow-growing tumor but rather a fast-growing one. Choice B is incorrect as osteosarcoma is not typically solitary but can involve multiple lesions. Choice D is incorrect as osteosarcoma primarily affects the medullary (marrow) cavity of bones, rather than infiltrating the trabeculae in spongy bone and surrounding tissue.

Correct Answer: B

Rationale: The correct answer is B: Underexcretion of uric acid. In gouty arthritis, the crystallization within the synovial fluid of the affected joint is caused by the underexcretion of uric acid, leading to the accumulation and subsequent crystallization of urate crystals. Choice A, destruction of proteoglycans, is incorrect as it is not directly related to the crystallization process in gouty arthritis. Choice C, overexcretion of uric acid, is incorrect because gout is primarily associated with underexcretion or decreased excretion of uric acid rather than overexcretion. Choice D, increased absorption of uric acid, is also incorrect as the primary issue in gouty arthritis is the body's inability to properly eliminate uric acid.

Correct Answer: A

Rationale: The correct answer is A. In the early stages of atheroma development, macrophages accumulate oxidized low-density lipoprotein (LDL) and transform into foam cells, leading to the formation of fatty streaks in the intima of blood vessels. This process is a hallmark of the initial stages of atherosclerosis. Choice B is incorrect as it describes the accumulation of lipids in the intima, which is a later event following foam cell formation. Choice C is also incorrect as it refers to the accumulation of proteins forming the fibrous cap, which occurs at a later stage to stabilize the atheroma. Choice D is incorrect as it describes the development of calcium and a necrotic lipid core, typically seen in advanced atherosclerosis rather than the early stages.

Correct Answer: B

Rationale: Multiple dark bands on the nails can be associated with malignant melanoma, a serious type of skin cancer. While dark bands on the nails can sometimes be a normal variant, they should not be ignored as they could also be a sign of a serious condition like melanoma. Nail fungus typically presents with different symptoms such as thickened, discolored, or brittle nails. Dark bands on the nails are not directly associated with aging.

Correct Answer: D

Rationale: Macular degeneration is a condition that affects the macula, a part of the retina responsible for central vision. It is primarily caused by impaired blood supply to the macula, leading to cellular waste accumulation and ischemia. This results in the death of photoreceptor cells and ultimately vision loss. Choices A, B, and C are incorrect because macular degeneration is not related to the loss of lens accommodation, detachment of the retina, or increased intraocular pressure. The correct answer directly addresses the underlying pathophysiology of macular degeneration.