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 small intestine absorbs nutrients during digestion. The small intestine absorbs small food particles through micro villi (small finger-like tentacles that line the small intestine wall). The nutrients then go to the veins and is carried through the body by blood. <br /><br /> The small intestine is also where most of the substrates bond with enzymes.