Question

Explain the electric conductivity of the heart.

Answer 1

. For each heartbeat, electrical signals travel through the conduction pathway of your heart. It starts when your sinoatrial (SA) node creates an excitation signal. This electrical signal is like electricity traveling through wires to an appliance in your home.23

Step-by-step explanation:

The heart is an electrically active organ that generates electrical signals to coordinate and regulate its contraction. The electric conductivity of the heart refers to its ability to conduct electrical impulses, which allows these signals to spread through the heart muscle and coordinate its rhythmic contractions.

The electrical activity of the heart is generated by specialized cells called pacemaker cells, which are located in the sinoatrial (SA) node in the right atrium. The SA node generates an electrical impulse that spreads through the atria, causing them to contract. The impulse then travels to the atrioventricular (AV) node, which acts as a gateway for the impulse to enter the ventricles. From there, the impulse travels down the His-Purkinje system, a network of specialized conducting fibers that stimulate the ventricles to contract.

The electric conductivity of the heart is determined by the properties of its cells and tissues. Cardiac muscle cells are electrically excitable, meaning they can generate electrical signals in response to stimuli. These cells are connected to each other by gap junctions, which allow electrical signals to pass from one cell to another. This enables the coordinated contraction of the heart muscle.

Answer 2

The heart's electric conductivity is controlled by a conducting system, featuring ion movement, that governs the rhythm and force of contractions. An electrocardiogram (ECG) measures these electrical impulses, whose patterns are indicative of the cardiac cycle and heart health.

Step-by-step explanation:

Electric Conductivity of the Heart

The electric conductivity of the heart is facilitated by a specialized system comprising conductive and contractile cells. The conducting system includes the sinoatrial (SA) node, internodal pathways, atrioventricular (AV) node, AV bundle of His, bundle branches, and Purkinje fibers.

These components distribute electrical impulses, initiating at the SA node, and regulate the heart rate.

Conductive cells generate action potentials starting with a prepotential phase that involves a slow influx of Na*, followed by a rapid exchange of Ca²+ for K*. Contractile cells, on the other hand, have a unique action potential with an extended plateau phase, significant for allowing complete contraction and effective blood pumping.

These variations in membrane potential are a consequence of ion movement, which is critical for the contractility and rhythmicity of cardiac muscle.

An electrocardiogram (ECG) is an external measurement of these electric impulses and reflects the cardiac cycle. Recognizable points on the ECG include the P wave, which corresponds to atrial depolarization, the QRS complex for ventricular depolarization, and the T wave for ventricular repolarization.

Each feature of the ECG relates to specific events within the cardiac cycle, providing insights into heart function.

Blocks or disturbances in the conduction path, such as those occurring at the SA or AV nodes, can lead to arrhythmias and interrupt the normal cardiac cycle. Understanding the electric conductivity of the heart is crucial for diagnosing and treating cardiac disorders.