Exercise Physiology: Theory and Application to Fitness and Performance 9th Edition by Scott Powers, Edward Howley

Exercise 1

What are the major purposes of the cardiovascular system?

Step 1 of 2

Single cellular organisms like bacteria absorb nutrients and excrete wastes through simple diffusion. Since the size of these cells is small, such a simple mechanism works efficiently to meet the nutritional demand of the organisms. However, large multicellular organisms cannot absorb or distribute nutrients through simple diffusion. Therefore, an efficient mechanism was required by them to meet the constraints posed by their size. Circulatory system in higher organisms has evolved to efficiently distribute nutrients and excrete wastes.