What's More Directions: Use the description provided in your handout. Then classify each picture into what level of organization it belongs. Write your answers in your Science activity notebook, Cardiac ( Digestive Nervous 2 3 1 Coordinated contractions of cardiac tissue in the heart pump blood throughout the body. Although digestive systems take many forms in organisms throughout the world, the main function of digestion is to break down food so that it can be used for energy by the body. Nervous tissue is the main component of the brain and spinal cord which regulate and control body functions pasagot po plss