Final answer:
Ischemia refers to the oxygen deficiency in surrounding tissues, and it can result in cell death and severe impairment of brain or heart function. Anemia is a deficiency disease that occurs due to a lack of hemoglobin to carry oxygen to body cells.
Step-by-step explanation:
Ischemia refers to the oxygen deficiency in surrounding tissues. Even without total blockage, vessel narrowing can lead to reduced blood flow and subsequent hypoxia, which is a decreased supply of oxygen to the tissues. This can result in cell death and severe impairment of brain or heart function. Anemia, on the other hand, is a deficiency disease that occurs when there is not enough hemoglobin in the blood to carry oxygen to body cells. Therefore, option 5) ischemia is the correct answer.