N331 EKG Nursing Sample Test

1. Which location of the heart is normally the pacemaker site and usually has the fastest firing rate?

SA node

AV node

Bundle of His

Purkinje fibers

The SA node, or sinoatrial node, is located in the right atrium of the heart and is responsible for initiating the electrical impulses that regulate the heart's rhythm. It is often referred to as the natural pacemaker of the heart. The SA node has the fastest firing rate among the options given, making it the primary site for initiating the heartbeat.

Explanation

The SA node, or sinoatrial node, is located in the right atrium of the heart and is responsible for initiating the electrical impulses that regulate the heart's rhythm. It is often referred to as the natural pacemaker of the heart. The SA node has the fastest firing rate among the options given, making it the primary site for initiating the heartbeat.

2. Atrial depolarization is manifested on an EKG as _______.

U waves

QRS complex

T waves

P waves

Atrial depolarization is represented by the P waves on an EKG. The P waves indicate the electrical activity that occurs when the atria contract to pump blood into the ventricles. This depolarization wave spreads through the atria, causing them to contract and push blood into the ventricles. Therefore, the correct answer is P waves.

Explanation

Atrial depolarization is represented by the P waves on an EKG. The P waves indicate the electrical activity that occurs when the atria contract to pump blood into the ventricles. This depolarization wave spreads through the atria, causing them to contract and push blood into the ventricles. Therefore, the correct answer is P waves.

3. Which heart chamber pumps oxygenated blood into the systemic circulation?

Left Atrium

Right Atrium

Left Ventricle

Right Ventricle

The left ventricle is responsible for pumping oxygenated blood into the systemic circulation. It receives oxygen-rich blood from the left atrium and contracts to push the blood out into the aorta, which then distributes it to the rest of the body. The left ventricle has thicker walls compared to the other chambers of the heart, allowing it to generate enough force to pump blood throughout the entire body.

Explanation

The left ventricle is responsible for pumping oxygenated blood into the systemic circulation. It receives oxygen-rich blood from the left atrium and contracts to push the blood out into the aorta, which then distributes it to the rest of the body. The left ventricle has thicker walls compared to the other chambers of the heart, allowing it to generate enough force to pump blood throughout the entire body.

4. Why is there a delay in conduction time from the SA node to the AV node?

Delays occur throughout all sections of the conduction system.

The Na/ K pumps are fewer in number near the SA node.

To enable the atria to completely empty its contents into the ventricles.

Primary ventricular blocks

The delay in conduction time from the SA node to the AV node is necessary to enable the atria to completely empty its contents into the ventricles. This delay allows the atria to contract and pump blood into the ventricles before the ventricles contract. If there was no delay, the atria and ventricles would contract simultaneously, reducing the efficiency of the heart's pumping action. Therefore, the delay ensures that the atria have enough time to contract and empty their contents into the ventricles before the ventricles contract.

Explanation

The delay in conduction time from the SA node to the AV node is necessary to enable the atria to completely empty its contents into the ventricles. This delay allows the atria to contract and pump blood into the ventricles before the ventricles contract. If there was no delay, the atria and ventricles would contract simultaneously, reducing the efficiency of the heart's pumping action. Therefore, the delay ensures that the atria have enough time to contract and empty their contents into the ventricles before the ventricles contract.

5. Which of the following blood vessels supplies most of the oxygen and nutrients to the SA node?

Brachioradialis

Right coronary artery

Left coronary artery

Inferior coronary sinus

The SA node, also known as the sinoatrial node, is responsible for initiating the electrical signals that regulate the heart's rhythm. The right coronary artery is the blood vessel that supplies most of the oxygen and nutrients to the SA node. This artery branches off from the main artery of the heart and travels along the right side of the heart, providing blood flow to various areas including the SA node. Therefore, the right coronary artery is crucial in ensuring proper functioning of the SA node by delivering the necessary oxygen and nutrients.

Explanation

The SA node, also known as the sinoatrial node, is responsible for initiating the electrical signals that regulate the heart's rhythm. The right coronary artery is the blood vessel that supplies most of the oxygen and nutrients to the SA node. This artery branches off from the main artery of the heart and travels along the right side of the heart, providing blood flow to various areas including the SA node. Therefore, the right coronary artery is crucial in ensuring proper functioning of the SA node by delivering the necessary oxygen and nutrients.

6. What term refers to the rhythmic contraction and relaxation of the heart chambers?

Depolarization

Repolarization

Systole

Cardiac Cycle

The term "cardiac cycle" refers to the rhythmic contraction and relaxation of the heart chambers. This cycle includes two main phases: diastole, where the heart chambers relax and fill with blood, and systole, where the heart chambers contract and pump blood out. Therefore, the correct answer is "Cardiac Cycle."

Explanation

The term "cardiac cycle" refers to the rhythmic contraction and relaxation of the heart chambers. This cycle includes two main phases: diastole, where the heart chambers relax and fill with blood, and systole, where the heart chambers contract and pump blood out. Therefore, the correct answer is "Cardiac Cycle."

7. Decreased oxygen levels at the tissue level is known as?

Arterial pressure

Hypoxemia

Hypoxia

Cyanosis

Hypoxia refers to decreased oxygen levels at the tissue level. It occurs when there is insufficient oxygen supply to the body's tissues. This can be caused by various factors such as reduced blood flow, lung diseases, or high altitudes. Hypoxia can lead to symptoms such as shortness of breath, confusion, and cyanosis (bluish discoloration of the skin). Arterial pressure refers to the pressure of blood in the arteries, hypoxemia refers to low oxygen levels in the blood, and cyanosis refers to the bluish discoloration of the skin due to lack of oxygen.

Explanation

Hypoxia refers to decreased oxygen levels at the tissue level. It occurs when there is insufficient oxygen supply to the body's tissues. This can be caused by various factors such as reduced blood flow, lung diseases, or high altitudes. Hypoxia can lead to symptoms such as shortness of breath, confusion, and cyanosis (bluish discoloration of the skin). Arterial pressure refers to the pressure of blood in the arteries, hypoxemia refers to low oxygen levels in the blood, and cyanosis refers to the bluish discoloration of the skin due to lack of oxygen.

8. After having several Stokes-Adams attacks over 4 months, a client reluctantly agrees to implantation of a permanent pacemaker. Before discharge, the nurse reviews pacemaker care and safety guidelines with the client and spouse. Which safety precaution is appropriate for a client with a pacemaker?

Stay at least 2′ away from microwave ovens

Never engage in activities that require vigorous arm and shoulder movement

Avoid going through airport metal detectors

Avoid having magnetic resonance imaging (MRI).

A pacemaker is a device that helps regulate the heartbeat. It consists of a small generator and leads that are implanted in the heart. Magnetic resonance imaging (MRI) uses powerful magnets and radio waves to create detailed images of the body. The strong magnetic field of an MRI can interfere with the function of a pacemaker and cause it to malfunction. Therefore, it is important for clients with pacemakers to avoid having MRI scans to ensure their safety and the proper functioning of the pacemaker.

Explanation

A pacemaker is a device that helps regulate the heartbeat. It consists of a small generator and leads that are implanted in the heart. Magnetic resonance imaging (MRI) uses powerful magnets and radio waves to create detailed images of the body. The strong magnetic field of an MRI can interfere with the function of a pacemaker and cause it to malfunction. Therefore, it is important for clients with pacemakers to avoid having MRI scans to ensure their safety and the proper functioning of the pacemaker.

9. What is the primary function of the aortic valve in the heart?

Prevents backflow of blood into the left atrium

Prevents backflow of blood into the right ventricle

Prevents backflow of blood into the left ventricle

Prevents backflow of blood into the right atrium

The primary function of the aortic valve in the heart is to prevent the backflow of blood into the left ventricle. When the left ventricle contracts, the aortic valve opens, allowing blood to be pumped out into the aorta and the rest of the body. After the contraction, the aortic valve closes to prevent blood from flowing back into the left ventricle, ensuring that blood only flows in one direction. This helps maintain the efficient circulation of blood throughout the body.

Explanation

The primary function of the aortic valve in the heart is to prevent the backflow of blood into the left ventricle. When the left ventricle contracts, the aortic valve opens, allowing blood to be pumped out into the aorta and the rest of the body. After the contraction, the aortic valve closes to prevent blood from flowing back into the left ventricle, ensuring that blood only flows in one direction. This helps maintain the efficient circulation of blood throughout the body.

10. EKGs can determine the contractility of the heart.

True

False

EKGs, also known as electrocardiograms, are not used to directly determine the contractility of the heart. Instead, they are used to measure the electrical activity of the heart and diagnose various heart conditions such as arrhythmias. Contractility, on the other hand, refers to the ability of the heart muscle to contract and pump blood effectively. While EKGs can indirectly provide information about the heart's contractility by detecting abnormalities in its electrical signals, they do not directly measure or determine contractility. Therefore, the statement is false.

Explanation

EKGs, also known as electrocardiograms, are not used to directly determine the contractility of the heart. Instead, they are used to measure the electrical activity of the heart and diagnose various heart conditions such as arrhythmias. Contractility, on the other hand, refers to the ability of the heart muscle to contract and pump blood effectively. While EKGs can indirectly provide information about the heart's contractility by detecting abnormalities in its electrical signals, they do not directly measure or determine contractility. Therefore, the statement is false.