What is the primary function of the cardiovascular system?

The primary function of the cardiovascular system is the transport of nutrients and oxygen throughout the body. This system comprises the heart, blood vessels, and blood, working synergistically to circulate vital substances. Oxygen obtained from the lungs is delivered to cells, while nutrients from the digestive system are absorbed into the blood and transported to tissues and organs. This ongoing circulation is crucial for cellular metabolism, energy production, and overall homeostasis.

While protection against pathogens and hormonal regulation are important functions that occur in the body, they are not the primary focus of the cardiovascular system. Additionally, digestion is a separate process primarily handled by the gastrointestinal system, not the cardiovascular system. Therefore, the correct answer highlights the essential role of the cardiovascular system in maintaining life by facilitating the necessary transport of key substances.