The human body requires a constant supply of oxygen and nutrients to function properly, and metabolic wastes must be efficiently removed to avoid toxicity. This exchange of substances occurs through the circulation of body fluids such as blood, lymph, and interstitial fluid. The circulatory system includes the heart, blood vessels, and lymphatic vessels, which work together to transport and distribute these fluids throughout the body. Blood, as the primary fluid of the circulatory system, contains plasma and cellular components such as red blood cells, white blood cells, and platelets. The cardiovascular system pumps blood to distribute oxygen and nutrients to tissues and organs, while the lymphatic system collects lymph and returns it to the bloodstream. The regulation and balance of body fluids and circulation is critical for maintaining homeostasis and overall health.