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.
  the nutrients enter the blood in the small intestine. The lining of the small intestine is called the villi, that is were the blood is absorbed into the bloodstream.27 people found this useful. Edit. Share to:utrients enter the blood via the small intestine. The  nutrients, undigested food passes into the large intestine. There,  water and minerals diffuse into the minerals diff â¦ use into the blood  and wastes are removed from the body.  . ernest mitchell.