Factors such as adenosine and catecholamines alter heart rate by affecting the kinetics of
A)voltage-sensitive Cl⁻ channels.
B)voltage-sensitive Na⁺ channels.
C)funny channels.
D)voltage-independent K⁺ channels.

Question

Quizplus · Accepted Answer

Adenosine and catecholamines affect heart rate by altering the kinetics of the "funny channels" (also known as hyperpolarization-activated cyclic nucleotide-gated channels). These channels are responsible for the pacemaker activity in the sinoatrial node which sets the heart rate. Therefore, altering their kinetics can affect the heart rate. The other options (A, B, and D) do not play a significant role in heart rate regulation.

Factors Such as Adenosine and Catecholamines Alter Heart Rate by Affecting