Final answer:
Ruby the red blood cell's journey starts in the left atrium, goes through the left ventricle into the aorta, branches into arteries and arterioles delivering oxygen to tissues, then travels back via veins and venules to the right atrium and ventricle and finally through the pulmonary artery to the lungs.
Step-by-step explanation:
Once upon a time, in the bustling city of the left atrium, a red blood cell (RBC) named Ruby began her journey to deliver oxygen. Ruby had just arrived via the pulmonary veins, full of fresh oxygen from the lungs, ready to venture forth into the systemic circuit. Pumped by the rhythm of the mitral bicuspid valve, Ruby bid farewell to the atrium and surged into the vibrant muscular left ventricle.
With a whoosh, Ruby was propelled through the grand semilunar valve and embarked on the majestic aorta, the main thoroughfare from the heart to the rest of the body. Along the way, she took a detour to the coronary arteries, nourishing the heart's own tissues. Her odyssey continued through specific arterial branches, like the arterioles, meeting countless other RBC friends, as they distributed their precious oxygen to various specific tissues including muscles and organs.
After the grand exchange, Ruby, now weary and oxygen-poor, traveled back towards the heart through the specific veins and venules, each pathway leading to either the superior or inferior vena cava, depending on whether she was in the upper or lower part of the body. She entered the right atrium, waved hello to a neighbor entering through the opposite tricuspid valve, then plunged into the right ventricle for another round trip. After a brief moment, Ruby was propelled into the pulmonary artery, heading towards the lung capillaries for rejuvenation and another cycle of life-saving travel.