Excitation-Contraction Coupling in the Heart

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What is the primary function of calcium ions in the cardiac cycle?

Regulation of cardiac output

Initiation of muscle contraction (correct)

Regulation of blood pressure

Regulation of heart rate

What is the role of the transverse tubules in the cardiac cycle?

To facilitate the transmission of electrical signals (correct)

To regulate the contraction of cardiac muscle cells

To increase the surface area for gas exchange

To store energy for muscle contraction

During which phase of the cardiac cycle does the ventricle fill with blood?

Systole

Isovolumic contraction

Diastole (correct)

Isotonic contraction

What is the term for the amount of blood pumped by the heart per minute?

Cardiac output Signup and view all the answers

What is the relationship between heart rate and the duration of the cardiac cycle?

Heart rate increases as the duration of the cardiac cycle decreases Signup and view all the answers

What is the function of the atria in the cardiac cycle?

To act as primer pumps Signup and view all the answers

What is the function of Calcium ions in Excitation-Contraction Coupling?

To trigger muscle contraction through binding to troponin Signup and view all the answers

What is the primary function of the traverse tubules in cardiac muscle?

To facilitate the transmission of action potential Signup and view all the answers

During the cardiac cycle, what occurs during the refractory period?

The cardiac muscle is unable to respond to a new stimulus Signup and view all the answers

What is the main purpose of the Volume-Pressure Diagram during the cardiac cycle?

To illustrate the relationship between ventricular pressure and volume Signup and view all the answers

What is the correct sequence of events in the cardiac cycle?

Action potential, contraction, refractory period, relaxation Signup and view all the answers

What is the primary function of the heart as a pump?

To pump blood throughout the body Signup and view all the answers

Which of the following is NOT a mechanism of intrinsic regulation of heart pumping?

Chemical energy required for Cardiac Contraction Signup and view all the answers

What is the significance of the heart valves in the cardiac cycle?

To prevent backflow of blood in the heart Signup and view all the answers

What is the primary function of the Oxygen Utilization by the Heart during cardiac contraction?

To provide chemical energy for cardiac contraction Signup and view all the answers

What is the result of Stimulation of the Parasympathetic nerve fibers (vagus) on the heart?

Decreased heart rate and contraction force Signup and view all the answers

What is the relationship between the heart sounds and heart pumping?

Heart sounds are a result of heart pumping Signup and view all the answers

Which of the following is a mechanism of extrinsic regulation of heart pumping?

Control of the Heart by the Sympathetic and Parasympathetic Nerves Signup and view all the answers