MSN 570 Advanced Pathophysiology Final 2024

Correct Answer: A

Rationale: The correct answer is Vitamin B12. Vitamin B12 deficiency can lead to megaloblastic anemia, a condition characterized by the production of abnormally large and immature red blood cells. Lower extremity paresthesias, such as tingling or numbness, are common neurological symptoms associated with vitamin B12 deficiency. Folate deficiency can also cause megaloblastic anemia but is not typically linked to lower extremity paresthesias. Iron deficiency leads to microcytic anemia, not megaloblastic anemia. Vitamin K deficiency is associated with bleeding tendencies, not megaloblastic anemia or paresthesias.

Correct Answer: C

Rationale: The correct answer is C: Decline in kidney function. As people age, their kidneys may not work as effectively in conserving water and concentrating urine, leading to a higher risk of dehydration. Choice A is incorrect because more insensible losses do not directly relate to an increased risk of dehydration in the elderly. Choice B, an increase in muscle mass, is not a factor that leads to dehydration. Choice D, a decrease in fat, is also not a direct factor contributing to dehydration in the elderly.

Correct Answer: D

Rationale: The correct answer is 'Low-density lipoprotein (LDL) receptor mutation with defects in breakdown.' Primary hypercholesteremia is mainly caused by mutations in the LDL receptor, leading to impaired clearance of LDL cholesterol from the blood. This results in high levels of LDL cholesterol in the bloodstream. Choices A, B, and C are incorrect because they do not directly relate to the primary cause of primary hypercholesteremia.

Correct Answer: B

Rationale: The correct answer is 'Herpes simplex I virus.' This disorder is known as Staphylococcal scalded skin syndrome (SSSS), where a Staphylococcus aureus organism produces an exfoliative toxin leading to skin exfoliation and large blister formation. Choices B, C, and D are incorrect. Herpes simplex viruses (I and II) cause different types of skin lesions and do not lead to exfoliation and blister formation. Necrotizing fasciitis is a severe soft tissue infection, while cellulitis is a bacterial skin infection that does not typically involve exfoliation and blister formation like in SSSS.

Correct Answer: B

Rationale: Postoperative adhesions are a common cause of mechanical small intestine obstruction. Adhesions can form after abdominal surgery, causing bands of scar tissue that may twist or pull the intestines, leading to obstruction. This is a more common cause compared to infection, tumors, or foreign bodies. Infection may lead to inflammation but is not a typical cause of mechanical obstruction. Tumors and foreign bodies can cause blockages but are less common than postoperative adhesions.