Answer:
Increased heart rate and force of contraction
Explanation:
Beta receptors that are located on the heart muscle cells play a very important role in heart rate and the strength of each contraction in the heart.
When we are found to be in a stressful situation (one that stimulates our fight or flight response) our body produces adrenaline (also known as epinephrine) which then stimulates the β1 receptors in the heart muscle.
There are also β2 receptors that are stimulated through norepinephrine, and β2 receptors are located in the bronchioles of the lungs.