Cardiovascular Physiology: Electrical Impulse Conduction in the Heart

1. What are the specialised cells that initiate the electrical impulse in the heart?

The answer to the question is the Sinoatrial node (pacemaker) as it is specifically responsible for initiating the electrical impulse in the heart. The other options mentioned play different roles in the heart's electrical conduction system.

Explanation

The answer to the question is the Sinoatrial node (pacemaker) as it is specifically responsible for initiating the electrical impulse in the heart. The other options mentioned play different roles in the heart's electrical conduction system.

2. How is the electrical pathway initiated?

The Purkinje fibers begin the electrical pathway by conducting the action potential from the atria to the ventricles.

The sinoatrial node opens its sodium channels the fastest of any cardiac muscle cell which starts an action potential

The bundle of His is the first to open its sodium channels to begin the electrical pathway.

The atrioventricular node is responsible for initiating the electrical pathway in the heart.

In the heart, the electrical pathway is initiated by the sinoatrial (SA) node, also known as the heart's natural pacemaker, which opens its sodium channels the fastest to generate an action potential and start the electrical conduction process.

Explanation

In the heart, the electrical pathway is initiated by the sinoatrial (SA) node, also known as the heart's natural pacemaker, which opens its sodium channels the fastest to generate an action potential and start the electrical conduction process.

3. What is the second node of the electrical pathway in the heart and what is its function?

The Purkinje fibers distribute the electrical signal rapidly throughout the ventricles.

The Sinoatrial node initiates the electrical signal in the heart.

The Bundle of His conducts the electrical signal to the ventricles.

The Atrioventricular node is the second node in the electrical pathway of the heart responsible for slowing down the pulse to allow the ventricles to fill before contracting. The Sinoatrial node initiates the electrical signal, the Bundle of His conducts it to the ventricles, and the Purkinje fibers distribute the signal rapidly for efficient ventricular activation.

Explanation

The Atrioventricular node is the second node in the electrical pathway of the heart responsible for slowing down the pulse to allow the ventricles to fill before contracting. The Sinoatrial node initiates the electrical signal, the Bundle of His conducts it to the ventricles, and the Purkinje fibers distribute the signal rapidly for efficient ventricular activation.

4. What is the third part of the electrical pathway of the heart?

Interatrial septum

Sinoatrial node

Purkinje fibers

Bundle of His, Atrioventicular bundle.

The electrical pathway of the heart consists of the Sinoatrial node, Atrioventricular node, Bundle of His, and Purkinje fibers. The third part of this pathway is the Bundle of His and Atrioventricular bundle, which are responsible for transmitting the electrical impulses to the ventricles.

Explanation

The electrical pathway of the heart consists of the Sinoatrial node, Atrioventricular node, Bundle of His, and Purkinje fibers. The third part of this pathway is the Bundle of His and Atrioventricular bundle, which are responsible for transmitting the electrical impulses to the ventricles.

5. What is the final part of the electrical pathway of the heart?

The sinoatrial (SA) node initiates the electrical impulse in the heart.

The atrioventricular (AV) node delays the impulse to allow for the atria to contract properly before the ventricles.

The bundle of His transmits the impulse from the AV node to the Purkinje fibers.

The electrical pathway of the heart involves various structures that work together to coordinate the heartbeat. The Purkinje fibers are responsible for spreading the impulse to every other cell they are attached to, resulting in the contraction of the heart and the pumping of blood.

Explanation

The electrical pathway of the heart involves various structures that work together to coordinate the heartbeat. The Purkinje fibers are responsible for spreading the impulse to every other cell they are attached to, resulting in the contraction of the heart and the pumping of blood.

6. What is the fourth part of the electrical pathway of the heart?

SA node, the pacemaker of the heart.

Bundle branches which branch off from the bundle of His, down the Septum to the apex

AV node which delays the electrical signal to allow the atria to contract before the ventricles.

Purkinje fibers which spread the electrical impulses to the myocardial cells.

The correct answer is referring to the Bundle branches, whereas the incorrect answers describe other parts of the cardiac electrical pathway such as the SA node, Purkinje fibers, and AV node.

Explanation

The correct answer is referring to the Bundle branches, whereas the incorrect answers describe other parts of the cardiac electrical pathway such as the SA node, Purkinje fibers, and AV node.