Which is a primary function of the circulatory system?

Which is a primary function of the circulatory system?

• A. Transport oxygen and nutrients to cells
• B. Distribution of hormones
• C. Transportation of metabolic waste
• D. Regulation of nerve signals

Answer: (A)

The circulatory system’s main job is to move substances that cells need to stay alive and functioning. Delivering oxygen from the lungs and nutrients from the digestive system to every cell is essential because cells use oxygen to produce energy and nutrients to fuel metabolic processes. Without this delivery, cells can’t generate the energy they require to perform their tasks. Blood does carry other things too—hormones to their targets and metabolic wastes to excretion organs—but these are secondary roles that rely on the same transport network. The nervous system regulates nerve signals, not the circulatory system itself, so regulation of nerve signals isn’t a primary function of circulation. So, the core purpose is supplying cells with oxygen and nutrients.

The circulatory system’s main job is to move substances that cells need to stay alive and functioning. Delivering oxygen from the lungs and nutrients from the digestive system to every cell is essential because cells use oxygen to produce energy and nutrients to fuel metabolic processes. Without this delivery, cells can’t generate the energy they require to perform their tasks.

Blood does carry other things too—hormones to their targets and metabolic wastes to excretion organs—but these are secondary roles that rely on the same transport network. The nervous system regulates nerve signals, not the circulatory system itself, so regulation of nerve signals isn’t a primary function of circulation. So, the core purpose is supplying cells with oxygen and nutrients.