Cardiac Conduction System and Ion Movements Quiz

Play an AI-generated podcast conversation about this lesson

During the cardiac cycle, what is the significance of the P wave?

Represents atrial relaxation

Marks the beginning of ventricular systole

Indicates depolarization of the atria (correct)

Signifies repolarization of the ventricles

Which part of the cardiac cycle corresponds to ventricular relaxation?

Ventricular systole

Diastole

Isovolumic ventricular relaxation phase (correct)

Atrial systole

What is the primary function of an artificial pacemaker?

Correcting fibrillations

Interruption in the normal conduction pathway

Storing oxygen in muscle cells

Ensuring effective heart contractions through electrical impulses (correct)

Which phase of the cardiac cycle involves the highest pressure in the ventricles?

Ventricular systole Signup and view all the answers

What is the primary function of a defibrillator designed to correct?

Fibrillations Signup and view all the answers

How does an increase in stroke volume affect the end systolic volume (ESV)?

Decreases ESV Signup and view all the answers

What is the role of Ca++ channels at 0mV during repolarization?

They close to prevent premature contractions Signup and view all the answers

What would be the heart rate range of the Atrioventricular bundle if not for endocrine control?

30 - 40 times per minute Signup and view all the answers

What is the main purpose of an ECG or EKG?

To record electrical signals of the heart Signup and view all the answers

Which component of the heart's conduction system fires at the lowest rate?

Purkinje fibers Signup and view all the answers

What happens when Ca++ binds to troponin during a heart contraction?

It allows myosin and actin cross bridge formation Signup and view all the answers

What is the function of the atria in the heart?

Collect blood and push it into the lower chambers Signup and view all the answers

Which layer of the heart produces lubricating fluid for the pericardial cavity?

Epicardium Signup and view all the answers

Where is the cardiac notch located?

Inferior lobe of the left lung Signup and view all the answers

Which chamber of the heart connects to the aorta?

Left ventricle Signup and view all the answers

What is the size of a typical human heart?

About the size of a fist Signup and view all the answers

Which artery carries deoxygenated blood in the heart?

Pulmonary artery Signup and view all the answers

What is the function of endothelium in the heart?

Releases endothelins that regulate growth patterns of cardiac muscle cells Signup and view all the answers

Which chamber of the heart has a small contractile phase and contains pectinate muscles?

Right atrium Signup and view all the answers

What is the purpose of the moderator band in the heart?

Aids in cardiac conduction in the right ventricle Signup and view all the answers

Why do semilunar valves make an audible sound as they close?

Because they have no muscular attachments Signup and view all the answers

Which valves close due to papillary muscles contracting?

Atrioventricular valves Signup and view all the answers

What is anastomosis in relation to coronary circulation?

Interconnections of blood vessels to allow blood flow in case of blockage Signup and view all the answers

Which cells in the heart conduct impulses and contract to pump blood through the body?

Myocardial contractile cells Signup and view all the answers

Where are T tubules found in cardiac muscle cells?

Only at Z discs Signup and view all the answers

What is the percentage range for the normal ejection fraction in the heart?

50% - 70% Signup and view all the answers

Which phase of the heart sounds corresponds to the closing of semilunar valves?

S2 Signup and view all the answers

What is the formula for calculating Cardiac Output (CO)?

CO = HR * SV Signup and view all the answers

What might be a consequence of high heart rates leading to decreased filling time?

Decreased Stroke Volume Signup and view all the answers

Which nerve dominates the autonomic tone of the heart?

Vagus nerve Signup and view all the answers

What conditions can decrease heart rate?

Hypoxia and acidosis Signup and view all the answers

At what stage do atrioventricular valves typically form during fetal development?

Between weeks 5 - 8 Signup and view all the answers

What is the target range to maintain a high Cardiac Output during exercise?

$100 - 120$ bpm Signup and view all the answers