The effects of caffeine intake on the human body

The purpose of this experiment is to examine the effects of caffeine intake on the human body. ECG measurements were performed on five healthy individuals on two separate occasions; once after consuming approximately 80 mg of caffeine shortly before measurements were taken, and again with no prior caffeine intake. Measurements were also taken to observe the effects of exercise on heart rate, both with and without prior caffeine intake.
Introduction
Brief review of physiology:
Write a brief, lucid review of the physiology related to your
instrumentation/measurement project. Also provide some background on previous similar or related studies (literature review). Use the information available in journal articles, seminal textbooks and/or on-line resources. Make sure you cite them properly.