During physical activity metabolism speeds up and muscles require more oxygen and nutrients. How does the heart keep up with this demand? Choose all that apply.
The heart goes in tachycardia mode to deliver more oxygen to the muscles.
The heart beat has a steadily constant beat of 60 beats per minute.
The heart pumps faster (increased heart rate) and stronger (increased stroke volume).
An increased cardiac output helps deliver more nutrients and oxygen to the working muscles.
The lungs are the organs bringing oxygen to the muscles, the heart is not involved.