Which system includes the heart, blood vessels, and blood?

The cardiovascular system encompasses the heart, blood vessels, and blood, which work together to circulate oxygen, nutrients, hormones, and waste products throughout the body. The heart acts as a pump to propel blood through the network of blood vessels, which includes arteries, veins, and capillaries. This system is essential for maintaining homeostasis, facilitating communication between different body parts, and ensuring that tissues receive the necessary substances for their functions while removing waste products.

The other systems mentioned, such as the respiratory system, endocrine system, and nervous system, serve distinct functions. The respiratory system is primarily involved in gas exchange, facilitating the intake of oxygen and the expulsion of carbon dioxide. The endocrine system is responsible for hormone production and regulation, influencing various bodily functions over time. The nervous system controls and coordinates bodily activities through nerve signals, playing a critical role in reflexes, sensory perception, and voluntary movement. While all these systems contribute to overall health and function, only the cardiovascular system is specifically focused on the movement of blood and the transportation of materials throughout the body.