Think about how your body reacts if you start exercising. How do
the nervous, muscular, circulatory, and respiratory systems respond to
an increased oxygen demand?

The primary purpose of the cardiorespiratory system is to deliver adequate amounts of oxygen and remove waste from body tissues .  The purpose of cardiovascular regulation is maintaining adequate blood flow to all body tissues.  In addition, the circulatory system transports nutrients and aids in temperature regulation.  During exercise, the demand for oxygen to the muscles is 15 to 25 times greater than at rest.  The heart cannot accomplish this by itself, and does not work in isolation.  The respiratory system and the circulatory system function together as a “coupled unit” delivering the body’s oxygen and nutrients and taking away carbon dioxide and wastes to maintain homeostasis.

the overall balanced equation

6co2 + 6h2o > c6h12o6 + 6o2

sunlight energy

where: co2 = carbon dioxide

h2o = water

light energy is required

c6h12o6 = glucose

o2 = oxygen

its 42

i say its d?