Review Questions - The Heart

Which of the following is a positive inotrope?

Ca²⁺

What happens to preload when there is venous constriction in the veins?

It increases.

Which component of the heart conduction system would have the slowest rate of firing?

Purkinje fibers

The force the heart must overcome to pump blood is known as (blank).

afterload

Most blood enters the ventricle during (blank).

atrial diastole

In which septum is it normal to find openings in the adult?

atrioventricular septum

Which primitive area of the heart will give rise to the right ventricle?

bulbus cordis

The influx of which ion accounts for the plateau phase?

calcium

The two tubes that eventually fuse to form the heart are referred to as the (blank).

cardiogenic tubes

The (blank) layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.

endocardium

Which of the following is not important in preventing backflow of blood?

endocardium

The myocardium would be the thickest in the (blank).

left ventricle

Which of the following lists the valves in the order through which the blood flows from the vena cava through the heart?

tricuspid, pulmonary semilunar, bicuspid, aortic semilunar

The pulmonary trunk and aorta are derived from which primitive heart structure?

truncus arteriosus

Ventricular relaxation immediately follows (blank).

ventricular repolarization

In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?

It decreases.

Which of the following is unique to cardiac muscle cells?

Only cardiac muscle is capable of autorhythmicity.

The first heart sound represents which portion of the cardiac cycle?

closing of the atrioventricular valves

The earliest organ to form and begin function within the developing human is the (blank).

heart

The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer to ventricular contraction while no blood is being ejected?

isovolumic contraction

The cardiovascular centers are located in which area of the brain?

medulla oblongata

Of the three germ layers that give rise to all adult tissues and organs, which gives rise to the heart?

mesoderm

Which valve separates the left atrium from the left ventricle

mitral

Which portion of the ECG corresponds to repolarization of the atria?

none of the above: atrial repolarization is masked by ventricular depolarization

Which chamber initially receives blood from the systemic circuit?

right atrium