Anatomy Quiz - Cardiac Conduction - Quiz, Flashcards & Trivia

1. What structure serves as the pacemaker in the heart?

AV node

Bundle of His

SA node

Purkinje fibers

The SA node, or sinoatrial node, serves as the pacemaker in the heart. It is located in the right atrium and generates electrical impulses that regulate the heartbeat. These impulses cause the atria to contract and then travel to the AV node, Bundle of His, and Purkinje fibers, which coordinate the contraction of the ventricles. The SA node is responsible for initiating the electrical signals that control the heart's rhythm and rate.

Explanation

The SA node, or sinoatrial node, serves as the pacemaker in the heart. It is located in the right atrium and generates electrical impulses that regulate the heartbeat. These impulses cause the atria to contract and then travel to the AV node, Bundle of His, and Purkinje fibers, which coordinate the contraction of the ventricles. The SA node is responsible for initiating the electrical signals that control the heart's rhythm and rate.

2. The SA node is located:

In the lower left ventricle wall

In the septum between the atria and ventricles

In the septum between the left and right ventricles

In the upper right atrial wall

The SA node, also known as the sinoatrial node, is located in the upper right atrial wall. This is where the electrical impulses that regulate the heart's rhythm originate. The SA node acts as the natural pacemaker of the heart, sending out regular electrical signals that cause the atria to contract and initiate the heartbeat. From the SA node, the electrical signals travel through the atria and then to the ventricles, causing them to contract and pump blood throughout the body.

Explanation

The SA node, also known as the sinoatrial node, is located in the upper right atrial wall. This is where the electrical impulses that regulate the heart's rhythm originate. The SA node acts as the natural pacemaker of the heart, sending out regular electrical signals that cause the atria to contract and initiate the heartbeat. From the SA node, the electrical signals travel through the atria and then to the ventricles, causing them to contract and pump blood throughout the body.

3. At rest, a new impulse is generated by the pacemaker at the rate of about ___ per minute:

170

75

25

125

The correct answer is 75. This means that at rest, the pacemaker generates a new impulse approximately 75 times per minute. This indicates the normal resting heart rate, which is typically between 60 and 100 beats per minute.

Explanation

The correct answer is 75. This means that at rest, the pacemaker generates a new impulse approximately 75 times per minute. This indicates the normal resting heart rate, which is typically between 60 and 100 beats per minute.

4. The main function of the cardiac conduction pathway is:

To ensure coordinated muscle contraction in the chambers and effective pumping of blood

To increase and decrease the heart rate in response to exercise

To ensure that the heart muscle in the atria and ventricles all contracts at the same time

None of the above

The main function of the cardiac conduction pathway is to ensure coordinated muscle contraction in the chambers and effective pumping of blood. This pathway consists of specialized cells that generate and conduct electrical impulses, allowing the heart to beat in a synchronized manner. These impulses are responsible for initiating and coordinating the contraction of the atria and ventricles, ensuring that blood is efficiently pumped throughout the body. By ensuring coordinated muscle contraction, the cardiac conduction pathway helps maintain proper blood flow and overall cardiac function.

Explanation

The main function of the cardiac conduction pathway is to ensure coordinated muscle contraction in the chambers and effective pumping of blood. This pathway consists of specialized cells that generate and conduct electrical impulses, allowing the heart to beat in a synchronized manner. These impulses are responsible for initiating and coordinating the contraction of the atria and ventricles, ensuring that blood is efficiently pumped throughout the body. By ensuring coordinated muscle contraction, the cardiac conduction pathway helps maintain proper blood flow and overall cardiac function.

5. The fibers that conduct the impulse to the ventricles are known as the:

SA node

AV bundle

Right bundle branch

Purkinje fibers

The fibers that conduct the impulse to the ventricles are known as the AV bundle. The AV bundle, also known as the atrioventricular bundle or bundle of His, is a collection of specialized muscle fibers located in the heart. It is responsible for transmitting electrical signals from the atria to the ventricles, allowing for coordinated contraction and efficient pumping of blood. The AV bundle is an essential component of the heart's electrical conduction system.

Explanation

The fibers that conduct the impulse to the ventricles are known as the AV bundle. The AV bundle, also known as the atrioventricular bundle or bundle of His, is a collection of specialized muscle fibers located in the heart. It is responsible for transmitting electrical signals from the atria to the ventricles, allowing for coordinated contraction and efficient pumping of blood. The AV bundle is an essential component of the heart's electrical conduction system.