A&P Ch. 20

The following are structural components of the conducting system of the heart. 1. Purkinje fibers 2. AV bundle 3. AV node 4. SA node 5. bundle branches

4, 3, 2, 5, 1

The following is a list of vessels and structures that are associated with the heart. 1. right atrium 2. left atrium 3. right ventricle 4. left ventricle 5. venae cavae 6. aorta 7. pulmonary trunk 8. pulmonary veins

5, 1, 3, 7, 8, 2, 4, 6

The bicuspid or mitral valve is located

between the left atrium and left ventricle

Blood returning to the heart from the pulmonary circuit first enters the

left atrium

The coronary sulcus is a groove that

marks the border between the atria and ventricles

Blood leaves the right ventricle by passing through the

pulmonary valve

The right ventricle pumps blood to the

right and left lungs

Blood returning to the heart from the systemic circuit first enters the

right atrium

The pulmonary semilunar valve prevents backward flow into the

right ventricle

During ventricular systole, the

AV valves are closed

The first heart sound is heard when the

AV valves close

The volume of blood ejected from each ventricle during a contraction is called the

stroke volume

________ is to contraction as ________ is to relaxation.

systole; diastole & ejection; filling (both A and D)

The phase in the cardiac cycle when the mitral valve is closed and the aortic valve is open is the

systolic ejection phase

Which of the following is greater during left ventricular systole?

the peak pressure in the ventricle

Blood flowing into the heart from the venae cavae flows next through the ________ valve.

tricuspid

The left ventricle pumps blood to the

aorta

In cardiac muscle

at least half of the calcium ion required for contraction comes from outside the cell.

During the isovolumetric phase of ventricular systole, the

atrioventricular valves and semilunar valves are closed.

The long plateau phase of the cardiac muscle action potential is due to

calcium channels remaining open

As blood leaves the right ventricle it passes through the ________ and then into the pulmonary trunk.

conus arteriosus

The right atrium receives blood from the

coronary sinus, superior vena cava, and inferior vena cava (A, B, and C)

Cardiac output can be increased by all of the following except one. Choose the exception.

decreasing ejection fraction

Stroke volume depends on

end diastolic volume, the contractility of the ventricle, and the pressure required to pump blood into the aorta (A, B, and C)

In cardiac muscle, the fast depolarization phase of the action potential is the result of

increased membrane permeability to sodium ions