n. 1. Physical or mental weariness resulting from effort or activity. 2. Something, such as tiring effort or activity, that causes tiredness or weariness: the fatigue of a long hike. 3. Physiology The decreased capacity or complete inability of an organism, organ, or part to function normally because of excessive stimulation or prolonged exertion. 4.
blood - the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets; blood carries oxygen and nutrients to the tissues and carries away waste products; the ancients believed that blood was the seat of the emotions
Artery simply refers to the direction in which blood is flowing. In this case, it means it is flowing away from the heart. Veins mean it is flowing toward the heart arteries carry blood away from the heart. To transport oxygenated blood though the system and into the veins to be oxygenated.