Which role is attributed to the base in the acid-base balance?

Choice A rationale:

Purpura refers to purple or red discolorations on the skin caused by bleeding underneath the skin. It is larger than petechiae and ecchymosis and could be a sign of a more serious underlying condition. Petechiae are small, red or purple dots that appear on the skin due to minor bleeding from broken capillaries. In the context of leukemia and thrombocytopenia (low platelet count), petechiae are common due to impaired clotting mechanisms.

Choice B rationale:

Bruising occurs due to damage to blood vessels underneath the skin, resulting in the leakage of blood into the surrounding tissues. Bruises are typically larger than petechiae and can occur with various conditions, including trauma. In this case, the small 1-mm red macules are more indicative of petechiae.

Choice D rationale:

Ecchymosis refers to a larger area of subcutaneous bleeding or bruising. It is larger than both petechiae and purpura and often results from more significant trauma or bleeding disorders. The description of multiple 1-mm red macules is characteristic of petechiae rather than ecchymosis.

Choice A rationale:

Spasm of a major coronary artery, also known as variant (Prinzmetal's) angina, typically occurs at rest and is not necessarily provoked by exertion. The patient's chest pain is exacerbated by exertion, making this choice less likely.

Choice B rationale:

Exposure of the thrombogenic surface to plaque refers to acute coronary syndromes like unstable angina or myocardial infarction. While plaque rupture and thrombosis can cause myocardial ischemia, the characteristic feature of these conditions is chest pain that may not be relieved by rest, unlike the patient described here.

Choice D rationale:

Myocardial ischemia secondary to microvascular disease, also known as cardiac syndrome X, is a condition where chest pain occurs without significant coronary artery stenosis. However, this condition usually affects women, and the pain is often unrelated to exertion. In the given case, the pain is provoked by exertion, making this choice less likely.