Chapter 19 Review Questions Flashcards
What is not important in preventing backflow of blood?
Endocardium
What valve separates the left atrium from the left ventricle?
Mitral
List the valves in the order through which the blood flows from the vena cava through the heart?
Tricuspid, pulmonary semilunar, bicuspid, aortic semilunar
Which chamber initially receives blood from the systemic circuit?
Right atrium
What layer secretes chemicals that help to regulate ionic environments and strength of contraction and serve as powerful vasoconstrictors.
Endocardium
The myocardium would be the thickest in the
Left ventricle
In which septum is it normal to find openings in the adult?
Atrioventricular septum
What is unique to cardiac muscle cells?
Only cardiac muscle is capable of autorhythmicity
The influx of which ion accounts for the plateau phase?
Calcium
What portion of the ECG corresponds to depolarization of the atria?
None of the above: atrial repolarization is masked by ventricular depolarization
Which component of the heart conduction system would have the slowest rate of firing?
Purkinje fibers
The cardiac cycle consists of a distinct relaxation and contraction phase. Which term is typically used to refer ventricular contraction while no blood is being ejected?
Isovolumic contraction
Most blood enters the ventricle during
Atrial diastole
The first heart sound represents which portion of the cardiac cycle?
Closing of the atrioventricular valves
Ventricular relaxation immediately follows
Ventricular repolarization
The force the heart must overcome to pump blood is known as
After load
The cardiovascular centers are located in which area of the brain?
Medulla Oblongata
In a healthy young adult, what happens to cardiac output when heart rate increases above 160 bpm?
It decreases
What happens to preload when there venous constriction in the veins?
It increases
Which of the following is a positive inotrope?
Ca2+
The earliest organ to form and begin function within the developing human is the
Heart
If the the germ layers that give to all adult tissues and organs, which gives rise to the heart?
Mesoderm
The two tubes that eventually fuse to form the heart are referred to as the
Cardiogenic tubes
Which primitive area of the heart will give rise to the right ventricle?
Bulbus cordis
The pulmonary trunk and aorta are derived from which primitive heart structure?
Truncus arteriosus
