As your skeletal muscles contract during physical activity, more blood is returned to the heart. Which variable would be affected? 

What allows a cell to respond to a hormone?

Which heart cells are responsible for setting the basic rhythm of heart beat? 

Which formed element can be described as complete cell?

Which body activity would be most affected if a patient lacked an adequate number of leukocytes?

What fibrous structure functions to anchor the atrioventricular valves (to papillary muscles from ventricular wall) in a closed position and prevent backflow of blood during ventricular contraction?

Hypertension increases _________, resulting into reduced stroke volume. 

Cardiac muscle cells are present in the ____________ of heart wall.

Which of the following hormones is a part of the short term response (rather than the long term response) to stress?

Which heart cells are responsible for setting the basic rhythm of heart beat?