As your body works harder, what happens to your HEART rate?
What important substance is replenished as blood flows through your heart?
Where does digestion start?
Your lungs are part of which body system?
Which part of your digestive system absorbs nutrients into your blood stream?
If you take a rest after running a mile, what happens to your BREATHING rate?
Which system pumps blood through your body?
When Dr. Jeff bends his arms to lift the weight, what is happening to his bicep muscle?
What happens to what's left of our food after it goes through the intestines?
As you exercise, your circulatory systems works with what other system to take in oxygen?