The Pacemaker of the Heart - SA and AV Nodes Made EASY!

The video explores the pacemaker potential in the heart's SA and AV nodes, explaining their roles in generating impulses that cause the heart to beat. It details the movement of ions like sodium, potassium, and calcium across cell membranes, leading to changes in membrane potential and the processes of depolarization and repolarization. The video also discusses what happens if the SA node malfunctions and how the AV node can compensate. It concludes with an interactive question to engage viewers in further discussion.

What is the primary function of the SA node in the heart?

• To act as a backup pacemaker

• To generate electrical impulses automatically

• To regulate blood pressure

• To contract and pump blood

Where is the AV node located in the heart?

• In the left ventricle

• In the lower back section of the interatrial septum

• Near the superior vena cava

• In the right atrium

What is the role of the bundle of His in the heart?

• To regulate heart rate

• To conduct signals from the AV node to the ventricles

• To contract the heart muscles

• To generate electrical impulses

Which ion has a higher conductance in the SA node, leading to depolarization?

• Potassium

• Calcium

• Sodium

• Chloride

What happens when the membrane potential reaches -40 millivolts in the SA node?

• Voltage-gated potassium channels open

• Voltage-gated sodium channels open

• The cell becomes hyperpolarized

• Voltage-gated calcium channels open

If the SA node fails, which node can take over as a pacemaker?

• The AV node

• The Purkinje fibers

• The left atrium

• The bundle of His

What might be required if both the SA and AV nodes fail to maintain adequate heart rhythm?

• A heart transplant

• An artificial pacemaker

• Increased physical activity

• Dietary changes