The circulatory system consists of three independent systems that work together: the heart (cardiovascular), lungs (pulmonary), and arteries, veins, coronary and portal vessels (systemic). The system is responsible for the flow of blood, nutrients, oxygen and other gases, and as well as hormones to and from cells
Despite the ominous weather and extremely dangerous conditions, the author faces the glacier and is moved by its beauty. He uses his past experience to bolster his confidence.