Cardiac Physiology

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Which chamber of the heart connects to the pulmonary trunk?

Right ventricle (correct)

Right atrium

Left atrium

Left ventricle

What is the function of the atria in the heart?

Collect blood and push it into the lower chambers (correct)

Separate oxygenated and deoxygenated blood

Hold blood and empty into the atria

Pump blood out to the body or lungs

Which layer of the heart produces fluid in the pericardial cavity?

Epicardium

Parietal layer

Myocardium

Visceral layer (correct)

Where is the heart positioned in relation to the lungs?

Below the lungs Signup and view all the answers

Which vessel carries deoxygenated blood in the heart?

Pulmonary artery Signup and view all the answers

What is the function of the auricles in the heart?

Hold blood and empty into atria Signup and view all the answers

What happens at 0mV in the cardiac muscle cells?

K+ channels open and Ca++ channels close Signup and view all the answers

What is the purpose of the long refractory period in the cardiac muscle cells?

To prevent premature contractions Signup and view all the answers

Which part of the heart's conduction system would fire at a rate of 15 - 20 times per minute?

Purkinje fibers Signup and view all the answers

Without endocrine control, how many times per minute would the AV node fire?

40 - 60 times Signup and view all the answers

What is the primary purpose of an Electrocardiogram (ECG or EKG)?

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

What is the main role of a defibrillator (AED) in correcting heart problems?

Delivers electrical impulses to ensure effective heart contractions Signup and view all the answers

During the cardiac cycle, what occurs during ventricular diastole?

Relaxation with semilunar valves open and atrioventricular valves closed Signup and view all the answers

What is the primary function of myoglobin in heart cells?

Stores oxygen in muscle cells Signup and view all the answers

Which phase of the cardiac cycle involves pumping blood into circulation?

Atrial systole Signup and view all the answers

What happens to the end diastolic volume (EDV) during ventricular systole?

Increases as blood flows toward the atria Signup and view all the answers

What is the normal range for stroke volume in the cardiac cycle?

$70 - 80$ mL Signup and view all the answers

What is the function of the endothelium in the heart?

Secrete vasoconstrictors Signup and view all the answers

Which structure divides the heart into chambers?

Septum Signup and view all the answers

What is the main function of the left ventricle in the heart?

Pushes blood into the aorta Signup and view all the answers

Which statement about coronary circulation is true?

Coronary veins bring oxygenated blood back to the right atrium. Signup and view all the answers

What is the role of autorhythmicity in cardiac muscle cells?

Initiate and propagate the action potential Signup and view all the answers

Where is the sinoatrial (SA) node located in the heart?

Superior and posterior wall of right atrium Signup and view all the answers

What is the function of Purkinje fibers in the heart?

Spread impulse around the ventricles Signup and view all the answers

Which characteristic differentiates cardiac contractile cells from myocardial conducting cells?

99% conduct impulses and contract Signup and view all the answers

What happens during the plateau phase in cardiac contractile cells?

Few K+ channels open. Signup and view all the answers

Why does altered blood flow produce a heart murmur during auscultation?

As a result of valve disorders. Signup and view all the answers

What is the primary cause of heart murmurs?

Turbulent blood flow Signup and view all the answers

Which sound is associated with the closing of semilunar valves?

S2 Signup and view all the answers

What is the normal range for Cardiac Output (CO) in liters per minute?

4 - 8 L/min Signup and view all the answers

What is the formula for Cardiac Output (CO)?

$CO = SV * HR$ Signup and view all the answers

Which factor can decrease Heart Rate according to the text?

Altered Na+ levels Signup and view all the answers

What is the main function of the nervous control of Heart Rate?

To regulate Heart Rate Signup and view all the answers

Which reflex results from increased blood in the atria stretching their walls?

Atrial reflex Signup and view all the answers

During exercise, what happens to the Cardiac Output?

Increases Signup and view all the answers

Which nerve dominates the autonomic tone of the heart?

Vagus nerve Signup and view all the answers

What is the percentage range for a normal Ejection Fraction?

50% - 70% Signup and view all the answers