Understanding the Cardiac Cycle

The video tutorial explains the cardiac cycle, focusing on pressure curves rather than volume, EKG, or phonocardiogram. It describes the heart's anatomy, including the atria and ventricles, and the flow of oxygen-poor and oxygen-rich blood. The tutorial details the changes in atrial and ventricular pressures, the role of valves, and the process of ventricular contraction. It also covers the increase in aortic pressure during blood ejection and the completion and restart of the cardiac cycle.

What is the primary focus of the cardiac cycle diagram in this video?

• Phonocardiogram

• Volume changes

• EKG readings

• Pressure curves

How many chambers does the heart have, and what are they called?

• Four chambers: left and right atrium, left and right ventricle

• Four chambers: two atria and two ventricles

• Three chambers: atria, ventricles, and septum

• Two chambers: atria and ventricles

What happens when the atrial pressure increases slightly?

• The ventricles contract

• The atria receive blood

• The aortic valve closes

• The atrioventricular valves open

Why do the atrioventricular valves close during the cardiac cycle?

• To prevent blood from flowing back into the atria

• Because the atrial pressure is higher than ventricular pressure

• Because the aortic pressure is higher than ventricular pressure

• To allow blood to flow into the ventricles

What causes the blood to be pushed into the aorta during the cardiac cycle?

• The atrial contraction

• The closure of the aortic valve

• The ventricular pressure exceeding aortic pressure

• The opening of the atrioventricular valves

What is the significance of the aortic valve opening?

• It allows blood to flow from the atria to the ventricles

• It marks the beginning of the ejection phase

• It prevents blood from flowing back into the ventricles

• It indicates the end of the cardiac cycle

What happens to the aortic pressure when the aortic valve closes?

• It drops to zero

• It increases slightly

• It remains constant

• It decreases sharply

What causes the slight increase in aortic pressure after the valve closes?

• Atrial contraction

• Ventricular relaxation

• Elastic recoil of the aorta

• Blood flowing back into the ventricle

What marks the beginning of a new cardiac cycle?

• The decrease in ventricular pressure

• The increase in atrial pressure

• The opening of the aortic valve

• The closure of the atrioventricular valves

What is the role of the atrioventricular valves during the cardiac cycle?

• To regulate the flow of blood into the aorta

• To prevent backflow of blood into the atria

• To allow blood to flow from the ventricles to the atria

• To maintain constant pressure in the ventricles