The exchange of nutrients and gases between the blood and tissue cells takes place at ______

The QRS complex of the ECG is associated with ______

A hiker slipped and fell into a ravine two days ago.  She was injured during the fall and is unable to climb out on her own. She hasn’t eaten since she fell.  Each of the hormones listed is involved in mobilizing her energy reserves EXCEPT:

Place the following in order of the propagation of a cardiac action potential

The two main circulatory routes are the ______

The peritoneum:

The middle layer of the heart wall is called ______

The direction of diffusion of gases between the pulmonary capillaries and the alveoli in the lungs is:

Blood passing through the tricuspid valve will enter the ______

Which of the following correctly describes how stroke volume is regulated?