What condition results from inadequate oxygen supply to tissues?

Ischemia is the condition that specifically refers to an insufficient blood supply to a tissue, leading to a lack of oxygen and nutrients required for cellular metabolism and function. This inadequate oxygen supply can result from various factors, such as blockage of blood vessels or reduced blood flow due to constriction. When tissues experience ischemia, they can begin to suffer damage or dysfunction due to oxygen deprivation, which can manifest as pain or other symptoms depending on the affected area.

In contrast, while cardiac arrest is a life-threatening condition where the heart fails to pump blood effectively, it is not solely defined by inadequate oxygen supply to tissues. Arrhythmia refers to irregular heartbeats that may or may not affect the oxygen supply to tissues directly, depending on their nature and severity. Angina pectoris involves chest pain due to ischemia specifically related to heart muscle, but it is a symptom rather than the condition itself. Ischemia thus provides the broadest and most direct definition of the inadequate oxygen supply to tissues, making it the most accurate answer.