U3-Electrocardiogram

What is stroke volume?

The amount of blood ejected with each contraction of the heart.

What factors influence stroke volume?

Gender, size, physical fitness, disease, and genetics.

What is cardiac output?

The volume of blood pumped by the heart per minute.

How does blood volume affect heart rate?

When blood volume decreases, heart rate increases.

What is depolarization in the context of heart function?

The state of stimulation that precedes contraction and causes the heart to contract.

What happens during repolarization?

Cells recover following contraction and the heart relaxes, allowing for chamber refilling.

What is represented by the P wave in an ECG?

Atrial depolarization and atrial contraction.

What does the QRS complex represent?

Conduction of electrical impulses through the ventricles.

What is the normal length of the PR interval?

Between 0.12 to 0.20 seconds.

What does the ST segment indicate?

The end of ventricular depolarization and the beginning of ventricular repolarization.

What does the T wave represent in an ECG?

Ventricular repolarization.

What is the significance of the J point?

It marks the junction of the QRS complex and the ST interval, indicating the end of ventricular depolarization.

What is the function of the SA node?

It acts as the heart's natural pacemaker, initiating the electrical impulse for heartbeats.

Where are the Purkinje fibers located?

They are located in the ventricles and are responsible for conducting impulses to trigger ventricular contraction.

What does the R-R interval measure?

The time from the start of one QRS complex to the start of the next QRS complex.

What is the Q wave in the QRS complex?

It represents the conduction of the impulse down the interventricular septum.

What is the normal duration of the QT interval?

It should normally measure less than one-half of the R-R interval.

What role do the chordae tendineae play?

They anchor the heart valves to the heart muscles, preventing backflow.

What is myocardial conductivity?

The ability of heart muscle cells to conduct electrical impulses.

What does the U wave represent?

Repolarization of the bundle of His and Purkinje fibers.

How does the heart's contractility relate to its function?

It refers to the heart's ability to contract and exert force during each heartbeat.

What is the heart's primary function?

To pump blood throughout the body to supply oxygen and nutrients.

What are the four chambers of the heart?

The right atrium, right ventricle, left atrium, and left ventricle.

What is diastole?

The phase of the cardiac cycle when the heart muscles relax and chambers fill with blood.

What role does the AV node play?

It transmits impulses from the atria to the ventricles, ensuring coordinated contraction.

What is the significance of heart rate?

It reflects how many times the heart beats per minute, indicating cardiovascular health.

How does exercise affect heart rate?

Exercise typically increases heart rate to supply more oxygenated blood to muscles.

What is arrhythmia?

An irregular heartbeat, which can be too fast, too slow, or erratic.

What are arterial vessels responsible for?

Carrying oxygen-rich blood away from the heart to the body.

What does blood pressure measure?

The force exerted by circulating blood on the walls of blood vessels.

What causes cardiac arrest?

An abrupt loss of heart function, often due to arrhythmias or other heart problems.