Quick Answer. The effects of caffeine start within 10 minutes after it is consumed, according to ScienceDaily. However, caffeine requires 45 minutes to reach its maximum concentration in the blood. Continue Reading.
The heart, blood, and blood vessels are the three structural elements that ... These nutrients enter the bloodstream by passing through the walls of the intestine.he heart, blood, and blood vessels are the three structural elements that ... These nutrients enter the bloodstream by passing through the walls of the intestine.
Making the world better, one answer at a time. When food is digested, it is absorbed into the blood from the small intestine walls. From there the blood is drained into the hepatic portal vein. The hepatic portal vein then goes to the liver.rom here they flow in the blood to the heart. The heart oxygenates this blood and returns it to the circulatory system. Blood flows into arteries and from these into capillaries in the tissues. This brings the blood in contact with the cells.