Which term describes decreased blood supply to a tissue or organ?

• A. Hypoxia
• B. Endogenous
• C. Exogenous
• D. Ischemia

Answer: (D)

The key idea is that this term refers to a failure of blood flow to a tissue or organ. Ischemia describes an insufficient blood supply, which means less oxygen and nutrients reach the tissue because arterial inflow (or venous outflow) is reduced or blocked. This vascular shortfall is the how and why behind decreased perfusion that the phrase points to.

It’s important to distinguish ischemia from hypoxia. Hypoxia means there is low oxygen in the tissue, which can occur even when blood flow is adequate—for example, if the blood’s oxygen content is low or the tissue can’t use what’s delivered. Ischemia, by contrast, specifically centers on the blood supply itself being inadequate. Endogenous and exogenous refer to sources or origins of something and don’t describe blood flow or oxygen delivery, so they aren’t the correct fit here.

So, decreased blood supply to a tissue or organ is best described as ischemia because it directly denotes impaired perfusion, the primary driver of reduced delivery of oxygen and nutrients to that tissue.