What is the main function of the circulatory system?

4 points
To transport nutrients and gases throughout the body
To process foods and extract nutrients/energy
To provide support and protection for the body
To react to external and internal stimuli

The main function of the circulatory system is to:

1. Transport nutrients and gases throughout the body: The circulatory system moves oxygen, nutrients, hormones, and waste products between cells and various organs, ensuring they receive the necessary nutrients and oxygen and remove metabolic waste.
2. Process foods and extract nutrients/energy: The digestive system processes and breaks down food, and the circulatory system carries the nutrients derived from food to the cells for energy production and other vital functions.
3. Provide support and protection for the body: The circulatory system helps maintain homeostasis by regulating body temperature, pH levels, and electrolyte balance. It also plays a role in immune responses, carrying immune cells, antibodies, and other substances that help fight infections and diseases.
4. React to external and internal stimuli: The circulatory system can respond to changes in the body's needs and external stimuli, such as increasing blood flow to muscles during exercise or constricting blood vessels to conserve heat in colder environments.