Khan Academy Static

Although your heart can beat independently, your nervous system is important as an external regulator. Your brain can tell your heart to speed up or slow down, depending on the scenario. For example, when you’re falling asleep, your nervous system will cause your heart to slow down, and 8 hours later when your phone alarm goes off, your nervous system will speed up your heartbeat! So even though your heart muscle beats by itself, the nerves can ramp up or down the speed. Check out the videos to learn more about how the nerves help to regulate the heart.

10935_Getting_a_new_heart.html

10931_Changing_the_AV_node_delay_chronotropic_effect.html

10934_Autonomic_nervous_system_effects_on_the_heart.html

10933_Increasing_ventricular_contractility_inotropic_effect.html

10932_Changing_the_heart_rate_chronotropic_effect.html