Which of the following mechanisms play a role in regulating heart rate?
Which of the following mechanisms play a role in regulating heart rate?
A) chemical messengers in the blood, such as epinephrine
B) nerves originating from the medulla lower part of the brain)
C) pacemaker cells within the heart
D) all of the above A to C)
E) only A and C

Question

Quizplus · Accepted Answer

Chemical messengers such as epinephrine, nerves from the brainstem, and pacemaker cells within the heart all play a role in regulating heart rate. Therefore, the best choice is (D) all of the above (A to C).

Which of the Following Mechanisms Play a Role in Regulating