"The circulatory system of man and the vertebrate animals can be considered as made up of a small number of organs or subordinate systems, which are easy to recognize anatomically, and the functions of which are on the whole quite distinct."
August Krogh was a Danish physiologist who won the 1920 Nobel Prize in Physiology or Medicine for his work on capillary regulation in skeletal muscle. He made foundational contributions to respiratory and comparative physiology.