MSN 570 Advanced Pathophysiology Final 2024

Correct Answer: C

Rationale: Irritable bowel syndrome (IBS) is a gastrointestinal disorder characterized by abdominal pain, bloating, and changes in bowel habits. While IBS can lead to symptoms like diarrhea or constipation, it typically does not cause anemia (choice A), is not generally associated with intestinal E. coli (choice B), and is not often associated with bloody diarrhea (choice D). However, IBS can indeed be associated with anxiety and/or depression (choice C) due to the gut-brain axis, a bidirectional communication system between the gut and the brain. This association is well-documented in IBS patients, highlighting the importance of considering psychological factors in managing the condition.

Correct Answer: D

Rationale: The correct answer is that ductal carcinoma in situ is characterized by malignant cells that have not invaded the stroma, making it a cancer precursor with a higher risk for invasive cancer compared to lobular carcinoma in situ. Choice A is incorrect because ductal carcinoma in situ is more common than lobular carcinoma in situ. Choice B is incorrect as it only partially describes ductal carcinoma in situ without mentioning its potential for progression to invasive cancer. Choice C is incorrect because it does not capture the complete characteristics of ductal carcinoma in situ, which include the risk for invasive cancer.

Correct Answer: B

Rationale: In this scenario, the rising lactic acid levels in a 65-year-old man after a coronary artery bypass graft could indicate bowel ischemia. Bowel ischemia can lead to anaerobic metabolism, causing an increase in lactic acid levels. Excessive sedation may cause respiratory depression but would not directly lead to rising lactic acid levels. Excessive volume infusion in the operating room might cause fluid overload but would not typically result in rising lactic acid levels. Mild hypothermia postoperatively could lead to shivering and increased oxygen consumption, but it is less likely to be the primary cause of rising lactic acid levels in this context.

Correct Answer: A

Rationale: Psoriasis is the correct answer because it is a chronic inflammatory skin condition characterized by features such as angiogenesis (formation of new blood vessels), immune cell activation (especially T cells), and excessive keratinocyte proliferation. This results in the typical symptoms seen in psoriasis, such as red, scaly patches on the skin. Melanoma is a type of skin cancer arising from melanocytes, not characterized by the features mentioned. Atopic dermatitis is a different skin condition involving eczematous changes, not specifically associated with the described characteristics of psoriasis. Urticaria is a skin condition characterized by hives and does not involve the same pathophysiological processes as psoriasis.

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.